Studies on the New Zealand Amphipodan Fauna No. 12. The Marine Families Stegocephalidae and Amphilochidae*
[Received by the Editor, September 21, 1954.]
Keys are given to the New Zealand genera and species of the families Stegocephalidae and Amphilochidae which are here revised. A new species of Amphilochus is described. A new genus is established for Cyproidca otakensis Chilton and two additional new species are described.
Introduction and Acknowledgments
The material which is described below has been made available from a number of sources, although unfortunately I have not been able to obtain specimens of all the species belonging to these two families previously recorded from New Zealand.
I wish to thank Mrs. S. Rind and Dr. R. Pilgrim for material reported on; Professor E. Percival and the Canterbury University College Council and Library for the use of Professor Chilton's specimens and literature; Dr. E. J. Batham of Portobello Marine Biological Station for helpful advice and assistance; and Professor L. R. Richardson for the use of facilities at Victoria University College.
Family Stegocephalidae G. O. Sars
Stebbing. 1906: 88.
Chevreux and Fage. 1925: 73.
Stephensen, 1925: 127.
“Head short, retiring Pereaon broad, deflexed in front. Sideplate 4 large. Antenna 1, accessory, flagellum 1- or 2-jointed. Antenna 2 seldom much longer than antenna 1. Upper lip bilobed. Lower lip without inner lobes. Mandible without molar or palp, accessory plate on one of the pair. Maxilla 1, inner plate with numerous setae, outer usually with 9 principal spines Maxilla 2, inner plate very broad and setose, outer narrow. Maxillipeds, plates broad rather than long, last 2 joints of palp narrow. Gnathopods 1 and 2 not subchelate. Peraeopod 3, 2nd joint not expanded. Uropod 3 biramous. Telson small”. —Stebbing, 1906.
Two genera belonging to this family are recorded from New Zealand. Barnard (1930) has suggested that it may be necessary to erect a new genus for the species Andaniotes simplex.
Key to New Zealand Genera of Stegocephalidae
|1 Mandible rather broad, cutting edge straight, smooth, maxilla 1 palp with 1 segment; telson cleft nearly to middle||Andaniotes Stebbing. 1897.|
|Mandible slender, elongated, toothed cutting edge on narrowly rounded apex; maxilla 1 palp has 2 segments; telson entire||Tetradcion Stebbing. 1899.|
[Footnote] * This study is part of a research programme being carried out at Portobello Marine Biological Station with the aid of a Nuffield Research Grant.
Genus Andaniotes Stebbing, 1897.
Stebbing, 1897: 30
Stebbing, 1906: 96
Schellenberg, 1931: 51
“Sideplate 4 slightly deeper than broad, overlapping 5th and part of 6th. Peraeon segment 1 subequal to 2nd and 3rd combined. Eyes wanting. Antennae subequal. Antenna 1, 1st joint peduncle very thick, longer than 2nd and 3rd combined, flagellum slender, with 4 joints, 1st longer than 1st of peduncle, 4th spiniform; accessory flagellum very small, 1-jointed Antenna 2, ultimate joint of peduncle shorter than penultimate, flagellum short. Epistome slightly carinate. Upper lip broader than deep, faintly emarginate. Lower lip, lobes narrow, very widely dehiscent, with minute upright spine at apex. Mandible, cutting edge straight, smooth, rather broad, tooth-like secondary plate on left mandible. Maxilla 1, inner plate with 7–11 plumose setae, outer with 9 spines, palp 1-jointed, with 7 spines. Maxilla 2, inner plate broad, densely fringed with spines and plumose setae, outer narrow, with 9 setae. Maxillipeds, inner plates very broad, with 3 spine-teeth but not many setae, outer not nearly reaching end of palp's 2nd joint, fringed with short spines. Gnathopod 1, 2nd joint broad, especially in male, 6th abruptly narrowed distally, rather shorter and a good deal narrower than the 5th. Gnathopod 2 slender throughout, 3rd joint elongate, 5th and 6th joints subequal, 6th narrowly oval. Peraeopods 1–5, 4th joint decurrent. Peraeopod 4, 2nd joint oblong, not very widely expanded. Peraeopod 5, 2nd joint very broadly oval, as long as rest of limb. Uropod 1–3 m male, peduncle robust, rami very short; uropod 1, outer ramus thick, inner thin; uropod 3, rami minute, outer 2-jointed, nearly twice as long as inner. In the female uropods 1–3, peduncle less robust, rami all slender, in uropod 3 subequal, nearly as long as peduncle. Telson oval, cleft nearly to middle.” —Stebbing, 1906.
Schellenberg comments that the spination and setation numbers must be deleted from this diagnosis since, with the exception of those of the 1st maxilla outer plate, they are variable and thus do not belong here. Also, in A. corpulentus the 6th pleon segment is not longer than the 4th or 5th as in Stebbing's diagnosis but only equally as long. I have made the latter correction but for lack of sufficient evidence on setation and spination I have left the diagnosis otherwise unaltered.
Key to New Zealand Species of Andaniotes
|1. Maxilliped palp of 3 segments. 1st and 2nd segments being combined to form fusiform segment, much wider than the end two segments||1. simplex Barnard, 1930|
|Maxilliped palp not as above||1. corpulentus (G. M. Thomson), 1882|
Andaniotes simplex Barnard, 1930.
Andaniotes simplex Barnard, 1930: 328–329. Fig. 7.
This species is recorded with A. corpulentus from “Terra Nova” Station 90, “off Three Kings Islands, 25.vin.11, 183 metres, bottom fauna”. I have no specimens, and there are none in the Chilton Collection.
Andaniotes corpulentus (G. M. Thomson), 1882.
Anonyx corpulentus G. M. Thomson, 1882: 231, Pl. 17 Fig. 1 a-f.
Andaniotes corpulentus Stebbing. 1897: 31. Pl. 8; 1906: 96; 1910: 575 Barnard, 1930: 328. Schellenberg, 1931: 51.
Andania [ unclear: ] Stebbing, 1888. 739–742, Pl. 37.
Strangely, this species is not included in the Chilton Collection, and I have no specimens of my own, so that I am unable to add any further information.
Localities: “Challenger” Station 168,” off New Zealand, July 8, 1874; 40° 28′ S. 177° 43′ E. depth 1,100 fathoms, bottom blue mud, bottom temperature 37.2° C.”; “Terra Nova” Station 90 (as above).
Distribution. New Zealand. New South Wales; Antarctic (Falkland Islands, Magellan Region); West Antarctic.
Genus Tetradeion Stebbing, 1899.
Stebbing, 1899: 207; 1906: 157.
Chilton, 1924: 632.
“Body short and stout, smooth, head small. Side-plates 1-4 together forming a continuous shield, the contiguous margins neatly fitting, fourth larger than first to third combined, fifth small, fitting into emargination of the fourth, sixth and seventh obsolete. Antennae 1 and 2 small. Mouthparts similar to those of Phippsia. Gnathopoda 1 and 2 similar, not subchelate, merus and carpus slightly produced, propod small. Peraeopoda 1 to 4 slender, basal joints not expanded, 5 greatly reduced, consisting of a small plate representing the basal joint. Uropoda short. Telson oval, short, entire.” —Chilton 1924.
Only one species is known.
Tetradeion crassum (Chilton), 1883. (Figs. 1-13.)
Cyproidea ? Chilton, 1883 80, Pl 3. Fig. 1.
Tetradeion crassum Stebbing, 1899: 207, Stebbing. 1906: 157. Chilton, 1924: 631-637. Figs. 1-20. Barnard, 1930: 329.
This species has been quite adequately described by Chilton (1924), and I intend to add only a few notes and drawings to complete his description. I have given a drawing of the whole animal since Chilton's later drawing (1924) does not accurately represent the shape of the 1st sideplate and slightly falsifies the shape of the 5th, at least as indicated by my specimen. It is just possible that Chilton's figures are based on a different species from mine, as also suggested by the 5th peraeopod and one or two other minor differences. However, in my opinion there is not sufficient evidence to distinguish two species and the differences noted may equally well be due to differences in age or sex of the specimens.
Part of the original type specimen is present in the Chilton Collection. It agrees reasonably well with the specimen that I have, and with others in the Collection except for a set of slides of Lyttelton material (Tray 114, 12-14) which appear to be those used for the 1924 drawings.
The 4th and 5th segments of the peduncle of the second antenna in my specimen are subequal, longer than the 3rd. The upper lip is asymmetrical. The 1st maxilla has 4 setae on the palp; the 2nd maxilla has about 30 setules on the inner plate, the outermost ones are strong and fine-combed. The palp setules have a double barb distally, the lower barb strong, the upper one hardly deserving the term but with a ring of very fine bristle-hooks In front view the effect is that of two small swellings separated by a constriction, the smaller upper one with its ring of bristle-hooks (Fig. 3).
In the first gnathopods, the posterior margin of the propod is not as strongly spined as figured by Chilton (1924), but is much more spined than the type which has only 5 or 6 spines. The sideplate is convex only on one margin, as shown in Chilton's Fig. 9, not as in his Fig. 1. The surface of the sideplate in this and other segments is strongly corrugated; this is barely apparent in one of Chilton's specimens, but not in any of the others. However, this is probably a matter of refractive indices of the various mounting media.
Text-fig. 1.—Tetradeion crassum (Chilton). 1, Adult 2, Upper lip. 3-5, Setules of maxilla 2 palp. 6, Corrugations of sideplate surface, gnathopod 1.7, Lower lip, end of outer plate. 8, Lower lip, end of outer plate. Chilton's Lyttelton material. 9, Peraeopod. 5.10 Peraeopod 5, ischium 11, Peraeopod 5, ischium, Chilton's Lyttelton material. 12. Epimeral plates 13. Uropod 3. Veocyproidea otakensis (Chilton). 14, Upper lip. 15, Lower lip, end of outer plate. 16, Mandible. 17, Maxilla. 2.18 Maxilliped. 19, Maxilliped, propod and dactylos. 20, Maxilliped, end of inner plate. 21 Maxilliped end of outer plate.
In the peraeopods, the merus is as long as the carpus, and in Pr 1 is about ⅔ propod length. In Pr. 5, the isehium is not as large as in Chilton's 1924 figure and has only two terminal setae. Its length is about 1/20th that of the basos, whereas in Chilton's specimen it is about 1/5th and has two setae about 2/3rd down the anterior margin. The type agrees with mine. The epimeral plates are as figured, the 3rd plates are somewhat damaged in my specimen and are not very satisfactory in the others, so I have indicated by a dotted line what appears to be the correct outline. The third uropod outer ramus has a distinct 2nd segment.
The distinctive shape of the animal is easily recognised and its mouthparts are equally characteristic.
The antennae peduncles, body segments and urosome are brown or slate, tending to violet ventrally except posterior 3rd of segment 4 and anteroventral portions of 1 to 4 which are whitish like remainder of body. Eyes black.
Localities Brighton, off Elzerina blainvilli, coll. Mrs. S. Rind, 5/4/54 (p. 129). Lyttelton. Chilton Collection. Tray 148/15-18 (B1-B4), 148/19, 114/12-14 (A1-A3), 13/9, Oamaru, Tray 13/10, Hawke Bay (fide Chilton), “Terra Nova” Station 135. North Cape, 1 ix. 11, 3 metres, night.
Family Amphilochidae G. O. Sars
Stebbing. 1906: 148.
Chevieux and Fage. 1925: 111.
Schellenberg. 1931: 92.
“Body short, stout. Antennae 1 and 2 short, subequal, accessory flagellum small or absent. Lower lip has inner lobes rudimentary or absent. Mandibles normal Maxillae 1 and 2 small. Maxilliped palp long. Gnathopod 1 moderately robust. Peraeopods slender. Broodplates large. Uropod rami slender. Telson entire, unarmed”. —Translated from Chevreux and Fage.
Seven species belonging to three genera are here described. One of these is a new genus instituted for Cyproidea otakensis Chilton, and two new species. The other two genera could easily be considered synonymous, but I have here maintained the status quo although treating them together in the key to their species.
Key to New Zealand Genera of Amphilochidae
|1 Sideplates 3 and 4, contiguous margins not exactly fitting; anterror margin of dactylos in gnathopods 1 and 2 not toothed; 3rd urosome segment not strongly keeled by telson-like structure||2|
|Sideplates 3 and 4, contiguous margins exactly fitting; both margins of dactvlos in gnathopods 1 and 2 toothed; 3rd urosome segment strongly keeled by telson-like structure||[ unclear: ]|
|2 Mandible molar expansion very small and unarmed [ unclear: ] Bate, 1862.|
|Mandible, molar expansion large and protruding; with a fluted [ unclear: ] surface||Gitanopsis Sars., 1892|
Genus Neocyproidea, n g
“Body short, stout. Sideplates 1 and 2 rudimentary, 3rd and 4th very large, confronted margins closely fitting, 6th partially concealed. Eyes well developed. Antennae 1 and 2 small. Antenna 1 peduncle rather stout; accessory flagellum absent or of 1 minute segment. Antenna 2. slender Mandible cutting edge with several teeth; spine-row well developed, molar strong, palp slender
or absent. Maxilla 2, outer plate with pair of flattened crescentic frayed spines on end, inner plate with pair at end, a pair down inner margin. Finger of maxilliped palp blunt. Gnathopods 1 and 2 subchelate, dactylos with surface and both margins toothed; 5th segment strongly produced posterodistally. Peraeopods 3-5, 2nd segment somewhat expanded. Third urosome segment strongly keeled by telson-like structure, not roofing over telson. Uropods 1-3, rami slender, unequal. Telson entire.”
The more important differences from Cyproidea are in the maxilliped finger, the first antennae which are short and Lysianassid-like, the dactylos in the first and second gnathopods, the mandible palp and molar process, the expansion of the second segment in Pr. 3-5, and the non-roofing over of the telson by the urosome keel. A comparison with figures for Cyproidea serratipalma (Schellenberg, 1938, Fig. 9) will show most of these differences quite strikingly.
Schellenberg (1938) makes these corrections to Stebbing's diagnosis of Cyproidea: “1st urosome segment long, 2nd short, 3rd roofing over the telson in a vertical lamina, 2nd peduncle segment of antenna 1 dorsally produced, 2nd antenna backwardly displaced, its 3rd peduncle segment lengthened”. He deletes “molar wanting”.
This, as he suggests, effectively excludes Neocyproidea otakensis. I have therefore erected this new genus for N. otakensis (Chilton), Neocyproidea peninsulae, n.sp. and Neocyproidea pilgrimi, n. sp. The type of the genus is N. otakensis.
Key to Species of Neocyproidea
|1. Mandibular palp absent; gnathopod 1, both margins and surface of dactylos strongly toothed||2|
|Mandibulat palp of 3 slender segments; anterior margin and surface of dactylos of gnathopod 1 very weakly toothed||N. peninsulac n. sp.|
|2 Gnathopod 1 has about 5 and 7 strong teeth on anterior and posterior margins, a few small spine-teeth on surface||N. otakensis (Chilton), 1900|
|Gnathopod 1 has about 6 and 13 strong teeth on margins a great number of smaller spine-teeth on surface||N. pilgrimi n. sp.|
Neocyproidea otakensis (Chilton), 1900. (Figs. 14-38.)
Cyproidia otakensis Chilton. 1900: 243-246. Pl. V.
Cyproidea otakensis Stebbing. 1906: 723.
“Light brown.” Body tumid, length about 3 mm.
Antennae. First: Lysianassid-like; peduncle nearly 3 times length flagellum, 1st segment width about ⅔ length; 2nd about ⅔ length 1st, 3rd nearly as wide as long, not ½ length 1st; flagellum of 3 distinct segments; 1st stout, tapering, base slightly narrower than 3rd peduncle segment, about as long as 2nd peduncle segment; inferior margin has 9 pairs of long flaccid sensory setae inferodistally, 2nd subsquare, about ¼ length 1st, 2 long setae inferodistally; 3rd ½ length 1st, 3 or 4 fine terminal setae. Accessory a blunt stump, nearly ½ length 1st flagellum segment, length twice width. Second: Peduncle, 2nd segment has promment gland cone extending ½ along 3rd, 3rd nearly as wide as long, 4th slightly more than twice length 3rd, slightly narrower; 5th as long as 4th. Flagellum not ½ peduncle length, of 4 segments; 1st segments ¾ length 5th peduncle segment, narrower; 2nd ⅔ length 1st; 3rd ½ 2nd; 4th slightly shorter than 2nd; slender; each has row of fine setae distally.
Mouthparts. Upper Lip: Bilobed, more or less symmetrical. Lower Lip: Outer lobes, inner margin finely bristled, finely toothed distally. Sug-
gestion of inner lobes proximally. First Maxillae: Inner plate short, 1 end seta. Outer has 8 stout teeth, several short setae. Palp as long, of 1 segment, has 1 or 2 fine end setae, 4 strong toothed spines. Second Maxillae. Inner plate has 2 strong-toothed flat crescentic spines on end; 2 in notch about ⅓ down inner margin; outer plate has 2 similar spines, stout short seta. Mandible: Cutting edge of about 6 teeth; accessory (on left) similarly toothed; molar process strong; spine-row of about 11 short spines; no sign of palp. (The Hauraki specimen has a structure reaching ¼ way from molar to tip of mandible which may be debris lying on the tip or may be the remnants of a quite stout 1-segmented palp). Maxilliped: Inner plates subrectangular, comparatively narrow, reaching end of palp merus; 2 minute dome-shaped spines on end margin, 2 longer ones down inner surface, a small seta also Outer plates reach end of carpus, outer margin convex, a large spine near apex, a seta inside it, the outer margin bristled, the inner finely comb-toothed as far as inner plate, about 6 long setae down rest of inner margin. Palp carpus ⅗ merus length; has 5 or 6 long setae on inner distal angle, merus width ½ length, inner distal angle has 1 seta Propod slightly longer than merus, 5 long setae on inner surface, angle produced in blunt thumb a little way along curved blunt finger which is about ¾ propod length.
Gnathopods. First: Sideplate quite rudimentary. Basos width not ⅓ length, a few fine short setae anteriorly. Ischium width ¾ length, length ¼ basos, [ unclear: ] posterodistally. Merus subtriangular; posterior margin convex, width more than ½ length, length more than ⅓ basos, strong spine-seta posterodistally. Carpus somewhat subtriangular, width ⅔ length, anterior margin ⅖ basos length, posterodistally produced ⅓ along behind propod; posterior margin of process has 3 single and 2 pairs of strong spines, end margin has 3 long strong spines, the spines finely tooth-combed Propod ⅔ basos length, widest about ⅓ where width nearly ⅓ length, margins slightly convex, the distal ⅔ of posterior with about 8 sets of single and paired strong fine-combed spines Dactylos strong, curved, ½ propod length, about 7 strong teeth on posterior margin, 5 or so on anterior; as well as numerous short fine spine-teeth on surface, the distal non-toothed ⅓ is a slender sharp claw. Second: Somewhat similar; basos width nearly ⅓ length. Ischium width ¾ length, length ¼ basos. Merus ⅓ basos length, subtriangular, width proximally ½ length, distally little more than ½ that, distal margin truncate has 5 or 6 long setae. Carpus subtriangular, greatest width ½ length, anterior margin ½ basos length, posterodistally produced ½ along propod, the process outer margin with 3 strong spine-setae, inner about 8, the end 3 strong finecombed spines. Propod as long, width ⅖ length, margins slightly convex especially posterior, distal ½ of posterior has 7 sets of 1 long and 1 short fine-toothed spines. Dactylos not ½ propod length, about 7 strong teeth on posterior margin, 5 or 6 on anterior.
Pereaopods. First: Sideplate ovate-rectangular, width slightly more than ½ length, anterior margin rounding convexly to oblique ventral, posterodistal angle acute but actual angle rounded, posterior margin sinuous with double flanged edge distally to imbricate with succeeding sideplate. Basos ⅔ sideplate length, width about ¼ length, a few fine setae on margins. Ischium not ⅓ length, 4 or 5 fine setae posteriorly. Merus piriform, ½ basos length, width about ⅓ length, 4 or 5 short setae on each margin. Rest missing Second: Sideplate greatly expanded, shield-like, anterior margin slightly convex about ⅓, barely concave distally, right-angled to ventral but angle tip truncate, ventral margin rounding
Text-fig. 2.—Veocyproidea [ unclear: ] (Chilton). 22, Antenna 1.23, Antenna 1, accessory flagellum. 24, Antenna 2.25. Maxilla 1, end of palp. 26. Gnathopod 1.27, Gnathopod 1, dactvlos. 28, Gnathopod 2. 29, Gnathopod 2, dactvlos. 30, Gnathopod 2. fine-toothed spines from propod posterioi margin. 31. Peraeopod 1.32, Peraeopod 4. 33, Utopods 2 and 3, telson.
convexly to posterior, posterior margin proximally excavate. Third. Sideplate posterior lobe slightly the larger and deeper; ⅔ basos depth. Basos narrowly expanded, width ½ length, slightly narrower distally, 6 or 7 short fine setae on slightly sinuous anterior margin, posterior barely concave medially. Ischium ⅓ basos length, width ½ length, 1 or 2 very short fine setae anteriorly. Merus piriform, posterodistal angle somewhat produced, anterior margin ½ basos length, width nearly ½ length, 3 or 4 short fine setae on each margin. Fourth: Sideplate ovate, depth about ¾ basos; basos ovately expanded, width about ⅔ length, widest distally, several very short setae on barely convex anterior margin; posterior straight except for rounded angles, naked. Ischium and merus as above except merus width about ¾ length. Fifth: Sideplate ovate, about ½ length basos anterior margin, ½ posterior; basos widest distally, anterior margin slightly convex, distal width about ⅘ anterior margin length, 4 or 5 short setae anteriorly; posterior margin produced in somewhat rounded lobe proximally, broad convex lobe distally as far as merus, ischium [ unclear: ] length of basos anterior margin, width ¾ length, 1 or 2 short setae anteriorly; merus piriform, posterior margin greatly convex and produced in strong acute posterodistal lobe probably to propod, a few fine setae each side of process; as wide as anterior margin which is ½ basos anterior margin length; posterior margin twice as long. Carpus (presumably of 5th) barely shorter than merus anterior margin, width ½ length, 3 or 4 short setae on anterior margin, propod as wide, ¾ length basos anterior margin; 5 or 6 short spines on anterior margin; dactylos strong, curved, about ½ propod length, small setal prominence near inner tip.
Epimeral Plates. First subtriangular, 2nd and 3rd more or less ovate, 2nd with small ridge running across anterior surface from anterior margin (but this may be abnormal).
Urosome. First urosome segment produced in telson-like keel with slightly concave upper surface extending back to about telson base. This is not, as Chilton seems to suggest, a vertical plate but is boat-shaped.
Uropods. First: Rami and peduncle subequal in length, rami very slender. Second: Peduncle about [ unclear: ] length inner ramus, outer ramus about ¾, the upper margins of narrow rami finely comb-pectinate throughout. Third: Peduncle nearly as long as inner ramus, outer nearly ⅔ as long; peduncle keeled superiorly and produced into acute superodistal angle; rami and peduncle superior margin all finely comb-pectinate. Telson: In profile boat-shaped; entire, subtriangular, reaching end of 3rd uropod peduncle.
Types: (Believed), Chilton Collection, Tray 12/13-15 (A1-A3). Paratype: C. 121.
Localities. Port Chalmers, New Zealand (surface net), types and paratypes.? off Kawau Island; Hauraki Gulf, 6 fathoms, “Hinemoa,” 29.XII.14, Tray 140/10.
Discussion. The main points to be noticed about this species are the very distinct teeth on the gnathopod dactyli which Chilton's paper speaks of as “setae”, and the lack of a mandibular palp. The shape and setation of the anterior margin of the basos of Pr. 3-5 are also noteworthy.
Neocyproidea peninsulae, n. sp. Figs. 39-50.
Small, black or dark olive-green, eyes reddish, body tumid, a pronounced bulge about the 2nd to 6th segments but sharply narrowed ventrally just above
the insertion of the sideplates. Length, 2 mm., depth, 1 ½ mm.; width, 1 ¼ mm. Like N. otakensis except as below.
Antennae. First: Flagellum of 4 segments, 1st with about 4 pairs of long flaccid sensory setae; the others with a pair each Minute accessory flagellum.
Mouthparts. Mandible. Spine-row of 9 stout spines; palp of (probably) 3 very slender segments, 1st about [ unclear: ] 2nd: 2nd ⅔ 3rd, a single seta on inner distal margin of 2nd. First Maxillae: Palp has 3 small toothed end spines, 2 fine setae.
Gnathopods. First: Carpal process has about 5 spines posteriorly, 3 on end. Propod width not ⅓ length, margins only slightly convex; single long spine-seta on outer margin about ⅘; 2 single and 3 pairs of fine combed spine-sctae on distal [ unclear: ] of posterior margin (although fewer on younger specimens). Dactylos more than ½ propod length, about 7 seta-like teeth on posterior margin, a much stouter distalmost one about [ unclear: ] ; several very small seta-like teeth on anterior margin, a few on surface. Second: Merus has single spine-seta [ unclear: ] along posterior margin, 5 on truncate end margin; carpal process has 3 stout spine-setae on outer margin, 3 on inner, 3 long stout spines on end margin, at least 2 of which are strongly comb-pectinate. Propod posterior margin distal ⅔ has up to 7 single and 3 paired sets of strong comb-pectinate spine-setae. Dactylos has about 5 seta-like teeth on posterior margin, the distalmost the strongest; anterior has about 3 very fine spines, 6 or 7 fine seta-like teeth on surface.
Peraeopods. First and Second: Basos anterior margin has quite strong fringe of relatively long fine setae; some on surface sideplate anterior to basos insertion also. Third: Basos anterior margin has about 5 long spine-setae. Fourth: Sideplate about ⅕ basos length; anterior margin has 5 or 6 quite long spine-setae. Fifth: Basos as wide as anterior margin is long, width about ⅗ posterior margin; the posterodistal angle less evenly rounded than in N. otakensis, about 6 or 7 quite strong spine-setae down anterior margin, 2 each on ischium and merus anterior margins also.
Uropods: Outer ramus 1st uropod about ¾ length inner; rami in all uropods finely pectinate on both margins, peduncle dorsal margins also. Telson: Subtriangular, length about twice width, about 3 fine bristle-setae on each margin, narrow apex bluntly pointed.
Types: Slides P: 120; paratypes. Slides P.122, P.125.
Localities: Off wharf-blocks from Ceramium, Portobello Marine Biological Station, Otago Harbour, 21/9/53. (P 120, 122, 125), coll D.E H.; off Ceramium on Pyura pachydermatina stalk. Aquarium Point, P.M.B.S, coll. D.E.H. 1/6/54; off wharf-blocks, P.M B.S, coll D.E.H., 27/8/53.
Discussion: The most characteristic features of this species are the general body shape and colour (which may or may not correspond precisely with that of N. otakensis); the feeble spination and pectination of the dactylos in each of the gnathopods; the presence of the 3-segmented mandibular palp and the strong setae on the anterior margin of the basos in the 3rd-5th peraeopods. There may be a mandibular palp in N. otakensis, but I have failed to find any definite indication of one in the two specimens I have seen. I am reasonably sure there is none in N. pilgrimi n.sp., unless by some mischance the palp has broken off cleanly at the base in all of the specimens which I have examined. The weak dactylos spination appears to be constant in the variously sized specimens of N. peninsulae which I have seen.
Text-fig. 3.—Neocyproidea otakensis (Chilton). 34. Paraeopod 2.35. Peraeopod 3.36 Peraeopod 5. 37, Peraeopod 5. end segments. 38. Epimeral plates Neocyproidea peninsulae n. sp. 39, Adult, side view. 40, Adult, dorsal view 41. Maxilla 1. end of palp. 42. Gnathopod 1, end segments. 43, Gnathopod 1, dactylos. 44, Gnathopod 2. end segments. 45, Gnathopod 2, dactylos 46, Uiosome keel 47, Telson.
The difference in general body shape and facies between this and the following species is quite marked, the one small, with the abdomen grossly tumid above the sideplates and quite noticeably pinched off below the sideplate insertion, dark in colour and keeping its pigment in alcohol for a considerable length of time if not always; the other about twice as large (4 mm.), evenly tumid with no sudden ventral constriction, and in alcohol white. I have no doubts about the distinctness of N. peninsulae from N. pilgrimi. I am somewhat less certain about the distinctness of either from N. otakensis. More particularly. I find N. otakensis and N. pilgrimi very close in detailed morphology with the exception of the gnathopod dactyli. I incline to the view that the differences in the spination of the dactyli in the three species are of specific rank.
The species name is derived from the Otago Peninsula, on which the Portobello Marine Biological Station is situated.
Neocyproidea pilgrimi, n.sp. (Figs. 51-62.)
Of moderate size (about 4 mm.), white in spirit and possibly in life although some of the preserved specimens show signs of a purplish-brown, eyes reddish-brown in spirit. Body evenly tumid, globose.
Length, 4 mm.; depth, 2 ½ mm. Like N. otakensis except as below.
Antennae: Small accessory flagellum present on first.
Mandibles: Left has spine-row of 14 curved sharp spines, right has 11 and a slender blunt spine distally. No sign of palp.
Gnathopods. First. Basos anterior margin has short fine setae of slightly varying lengths but not distally fringed as in N. peninsulae Carpal process has about 5 single and 2 pairs of fine-combed strong spine-setae on posterior margin; 3 strong end spines; propod as in N. otakensis; dactylos anterior margin has 5 or 6 strong teeth on medial ⅓. numerous very small spine-teeth proximal to them, posterior has about 13 distinct and quite strong teeth on proximal ⅔; the surface has numerous small and medium-length spine-teeth. Second: Carpal process has about 5 fine-combed strong spine-setae, posterior about 10 long setae, end has 3 strong spines; posterior margin of propod has about 8 pairs of 1 short, 1 long comb-pectinate stont spines. Dactylos has about 8 strong teeth on inner margin, about 5 quite strong and 8 or so short teeth and spine-teeth on outer, surface more or less naked.
Peraeopods.. First: Basos anterior margin strongly fringed with short setae. Second: Basos anterior margin strongly fringed with fine setae, width ⅓ length. Ischium width ½ length; posterior margin has several very short setae. Merus posterior margin straight, with 5 or 6 short spine-setae, length ½ width, anterior slightly convex with a few very short fine setae, anterodistal angle slightly produced, blunt Carpus linear, as long as merus, width about ¼ length, 4 small spines on posterior margin; propod almost as long and wide, 7 small spines on posterior margin. Dactylos about ½ propod length. Third, Fourth and Fifth: Proximal segments as in N. otakensis; merus of 4th, straight anterior margin is ½ basos length, has 4 small spines; posterior is convex and produced acutely ¾ down carpus, has several very short fine setae Carpus as long, width nearly ⅓ length. 3 spines on front margin, propod slightly longer, 5 short spines on anterior margin; dactylos about ½ propod length.
Uropods. First: Rami more or less subequal. Second: Outer ramus about ¾ length inner. Third: Outer ramus about [ unclear: ] length inner, inner barely longer
Text-fig. 4.—Neocyproidea peninsulae n.sp. 48, Mandible. 49, Peraeopod 4. 50, Peraeopod. 5. Neocyproidea pilgrimi n. sp. 51, Mandible. 52, Maxilla 1, end of palp. 53, Maxilla 2.54, Gnathopod 1, end segments. 55, Gnathopod 1, dactylos 56. Gnathopod 1, end of caipal process with spines. 57, Gnathopod 2, end segments. 58, Gnathopod 2, dactylos. 59, Peraeopod 1 60, Uropod 3.
than peduncle which has superodistal angle produced nearly ½ along outer ramus. In all uropods, peduncle and rami have both dorsal margins finely pectinate.
Types: Slides P.70, female. Paratypes: P.124, female of length 3 ½ mm., depth 2 ¼ mm.; width, 1 ½ mm; P.126, female.
Localities: Menzies Bay, Banks Peninsula, coll. Dr. R. Pilgrim, 1953 (Slides P.70, P124, P.126); Hawke Bay, ovigerous female from Chilton Collection (Slides C.123).
Discussion: The grounds on which these specimens have been given specific rank have already been detailed above. The doubts about its distinctness from N. otakensis will probably be resolved finally only by the availability of considerably more comparison material, particularly of N. otakensis. The general facies of the latter species may prove especially useful.
Genus Amphilochus Bate, 1862
Sars, 1892: 215.
Stebbing, 1906: 149.
Chevreux & Fage, 1925: 111.
Schellenberg, 1926: 301; 1942: 114.
“Body robust. Head with large rostrum, more or less curved, sharp. Sideplate 1 small, partly hidden by 2nd; 2nd-4th large; 5th with posterior lobe the larger. Antennae 1 and 2 with peduncle long, flagellum short, without accessory flagellum. Epistome rounded. Lower lip without inner lobes Mandible long, cutting edge denticulate, molar expansion very small and unarmed; right mandible has one accessory plate, palp slender. Maxilla 1 inner plate small, palp 2-segmented. Maxilla 2 inner plate larger than outer. Gnathopods 1 and 2 subchelate, carpus more or less prolonged, dactylos long. Peraeopods slender, subequal, 3rd to 5th with basos expanded. Rami of uropod 2 unequal; peduncle of uropod 3 longer than rami.”
This diagnosis is translated from Chevreux and Fage, but the “molar process feeble” of their diagnosis has been altered in accordance with Schellenberg's remarks on the separation of Amphilochus and Gitanopsis (Schellenberg, 1926: 301). This alteration, and the corresponding alteration in the diagnosis for Gitanopsis, actually re-introduce the characteristics which Sars used to separate the two genera.
Two species have been recorded from New Zealand; one of these belongs to Gitanopsis. However, this account adds a further new species.
Key to New Zealand Species of Amphilochus and Gitanopsis
|1. Molar process of mandible large and protruding with fluted triturating surface||2|
|Molar process of mandible very small and unarmed||3|
|2. Inner margin of lower lip medially incised; telson long and narrow, with 2 small terminal notches||Gitanopsis squamosa (G. M. Thomson)|
|Inner margin of lower lip medially smooth; telson ovate, smoothly rounded distally||Gitanopsis pusilloides Shoemaker|
|3. Gnathopod 2, hand not markedly longer than broad||Amphilochus marionis Stebbing|
|Gnathopod 2, hand at least 1 ½ times as long as broad||Amphilochus filidactylus n.sp.|
Amphilochus marionis Stebbing, 1888.
Amphilochus marionis Stebbing, 1888: 743, Pl. 38, Stebbing, 1906: 151, Stebbing, 1910: 577, Schellenberg, 1938: 17.
Gitanopsis marionis Schellenberg, 1931: 95.
Amphilochus marionis, Chilton, 1923: 240. Chilton, 1925a: 84-85 (not Stebbing).
Schellenberg (1938) has pointed out that Amphilochus marionis and Amphilochus squamosus are not synonymous, and that the latter in fact is a Gitanopsis. Chilton's two papers indicate clearly that his specimens also had the strong molar process of Gitanopsis.
The only sign of A. marionis in the Chilton Collection is fragmentary material mixed in a slide also containing G. squamosa. There is no indication of its locality and for the purposes of this paper it is best disregarded.
Schellenberg (1931) states that he has a small collection from Lyttelton Harbour which includes 2 specimens of A. squamosus and 2 of A. marionis. This satisfactorily establishes the presence of A. marionis in New Zealand waters.
Amphilochus filidactylus, n.sp. (Figs. 67-90.)
Gitanopsis pusilla, Stephensen, 1949: 8, Fig. 1 (not Barnard).
Eyes in spirit black, reniform; animals in life reddish with black spots. Length, 4 mm. Like Gitanopsis squamosa (cf. below) except for the following details.
Antennae. First: First segment of peduncle slightly shorter than 2nd; 3rd ⅔ 2nd, tufts of spines and spine-setae on superodistal angles of 1st and 2nd, single group ½ along 2nd superiorly. Accessory flagellum of 1 segment, ½ length 1st segment of flagellum, has 2 or 3 long end setae. Second: Peduncle, 3rd segment about ½ length 4th, as wide, superodistally produced in 2 small rounded projections, 1 with large spine-seta, about 3 spine-setae on superior margin; 4th has 3 sets of 1-6 spine-setae on each margin, these also on distal angles especially inferior; 5th not ¾ length 4th, 2 or 3 groups of 1 or more spine-setae on each margin, also on angles; flagellum of 8 segments, as long as 4th peduncle segment, 3 or 4 fine setae on each distal angle.
Mouthparts. Lower Lip: Inner margin notched medially, small rounded bristled boss distally, 2 sets of 3 long teeth on inner margin below. First Maxillae: Inner plate has 2 end setae; outer has 7 stout teeth, palp 3 short spines and 1 seta. Second Maxillae: Inner plate has approximately 11 fine end setae, 3 or 4 fine bristle-setae proximally. Outer has 3 end spine-setae, a few bristles outside these. Mandibles: Molar process a produced conical tubercle narrowing to small truncate tip; spine-row of about 19 spines, the lower 9 less strong and tending to be fused; right cutting edge of about 8 strong serrations, left of 10 or so fine serrations, accessory of about 16 fine serrations. Palp of 3 segments, 1st small, about ½ length 2nd, 2nd about ⅔ length 3rd, which has no setae, is finely bristle-combed, narrows to acute tip. Maxilliped. Inner plate has 2 very small, boss-like spines on end margin; outer plate distally rounded, has stout end spine, finely serrate margin, seta inside spine, a few down margin. Palp merus width ⅔ length, outer margin has 5 single setae, inner about 6, carpus almost as wide as long, length about ⅗ merus, seta ⅓ along outer margin, 2 or 3 on angle, inner margin has 7 or so on distal angle; propod width ½ length, length ⅔ merus; 1 or 2 spines at ⅓, ⅔ and distal angle of outer margin; 8 or so on inner distal angle, at their base 5 small blunt comb-fingers. Dactylos a straight sharp spike, little more than ½ propod length, inner margin finely combed.
Text-fig. 5.—Neocyproidea pilgrimi n. sp. 61, Peraeopod 2. 62, Peraeopod 4. Gitanopsis pusilla Barnard. 63, Gnathopod 1, end segments. 64, Gnathopod 1, dactylos and palm margins. 65, Gnathopod 2, end segments. 66, Gnathopod 2, dactylos and palm margins Amphilochus filidactylus n. sp. 67. Gnathopod 1. 68, Gnathopod 1, palm and dactylos. 69, Gnathopod 2. 70, Gnathopod 2, sideplate ventral margin. 71, Gnathopod 2, palm and dactylos. 72, Gnathopod 2, palm margin. 73, Telson.
Gnathopods. First: Sideplate somewhat trapezoid, anterodistally rounded with fine setae on margins. Basos proximal width about ¼ length, boatshaped with double anterior margin, concave between margins, to receive propod; anterior margins finely setose. Ischium about ⅕ basos; merus about ⅓ basos, subtriangular, about 4 spine-setae on posterior margin, 7 or 8 spine-setae on posterodistal angle. Carpus as long as ischium, distally widening to more than twice length, posterior ½ strongly spine-setose especially angle which extends nearly ½ along propod posterior margin. Propod width a little more than ½ length, margins convex, posterior rounding to convex distal palm margin and separated from it only by 2 small, stout defining spines; the palm has about 16 small setae slightly below finely serrate margin. Dactylos curved, as long as palm is wide, stout tooth on inner margin about ½ along, 12 or so fine comb-teeth inside tooth, dactylos stout except for last ⅕ which is noticeably filiform. Second: Sideplate ovately-subrectangular, width ½ length, angles rounded, margins finely setose. Basos as before, widest distally, distal width ⅓ length; ischium wider than long, length about ⅙ basos, merus subtriangular, length ⅓ basos, narrowing bluntly to a stout spine and several short spine-setae, 4 strong spines on posterior margin: reaching as far as propod base. Carpus subtriangular, anterior margin not ⅓ basos, posterior produced in long, slender, spoon-shaped process almost but not quite to palm defining angle, the process has 2 or 3 long terminal spine-setae, 10 or 11 short setae on inner margin. Propod ovate-rectangular, widest distally, distal width about ⅔ length, length ⅚ basos, lateral margins more or less straight, postero-distal angle rounding to fully crenulate slightly convex palm which is defined by 2 stout spines and has 9 or so fine setae below margin, stouter one inside dactylos base, dactylos as before.
Peraeopods. First: Like G. squamosa, perhaps more spinous. Second: Setae on posterodistal angle give crimped appearance as in Stebbing's A. marionis. Third: Sideplate posterior lobe deeper than anterior, almost basos length; basos ovate, anterior margin has about 18 short stout spines, posterior minutely and regularly setose; other segments seem comparatively strongly spined. Fourth and Fifth: Basos like Pr. 3, more strongly spined anteriorly than in G. squamosa.
Epimeral Plates: All have rounded anterodistal angle, slightly produced acute posterodistal angles; are subrectangular; 1st almost subtriangular; posterior margins slightly sigmoid; ventral have 4,14 and 16 spine-setae.
Uropods. First: Much the longest; peduncle slightly longer than subequal rami; has about 16 spines dorsally; rami have 7 or 8 spines on one or both margins, spines each in marginal serration. Second: Outer ramus about ⅔ peduncle length, inner ¾; outer has 5 and 2 marginal spines, inner has 4 and 5, the median margins finely pectinate. Third: much the smallest; outer ramus the shorter, has 4 spines on outer margin, 1 on pectinate inner; inner ramus as long as peduncle, 3 spines on inner margin, 5 on outer; the median margins finely pectinate; the spines in sharp serrated pockets; 4 or 5 spines on peduncle. Telson: Width about ⅔ length, narrowing distally from about ½ to rounded blunt tip.
Localities: Off Pyura pachydermatina stalk with encrusting Elzerina blainvilli, Portobello. Marine Biological Station, coll. D.E.H., 15/5/52.
Distribution: New Zealand; Tristan da Cunha.
Types: Slides P. 130, female.
Discussion. This species keys out according to Stephensen's key (1949) as G. pusilla or G. tortugae. G. pusilla is not very fully described, but I have speimens
Text-fig.. 6.—Amphilochus filidactylus n.sp. 74, Antenna 1. 75, Right mandible and cutting edge. 76, Left mandible. 77, Maxilliped, right half. 78, Maxilliped, end of inner plate. 79, Maxilliped, end of outer plate. 80, Maxilliped, end of palp. 81, Maxilliped, propod inner distal margin 82, Maxilla 1, end of palp. 83, Maxilla 2. 84, Lower lip, right half. 85, Peraeopod 3. 86, Peraeopod 3. posterior margin of basos. 87, Epimeral plates, 88, Uropod 2. 89, Uropod 3, 90, Uropod 3, margin of ramus.
from the Chilton Collection labelled as coming from Cape Town which appear to be G. pusilla, and they are markedly different from the specimens described above. I have taken the liberty of drawing the gnathopods of these Cape Town specimens for comparison (Figs. 63-66). It will be seen that they differ from the above in having a stouter dactylos with the prominent inner tooth ⅔ along instead of ½ along, and are not constricted to a filiform tip as in A. filidactylus. Since Barnard (1916) places his species in Gitanopsis, one may also expect a difference in the molar process. (Stephensen does not mention the molar process in his specimens.) A. filidactylus also lacks the single stout anterior propod spine of G. pusilla The telson, gnathopod shape (length of carpal process), and characteristic dactylos are distinctive for the species.
It is also obvious that my species is identical with or extremely close to that described by Stephensen (1949) as G. pusilla Barnard. With the exception of the projection which he figures and describes for the anterior margin of Gnathopod 1 basos, there is no difference which I can see between the two sets of specimens. I have therefore included his G. pusilla in the synonymy of A filidactylus.
Genus Gitanopsis G. O. Sars, 1892.
Sars, 1892: 223.
Stebbing, 1906: 153.
Schellenberg, 1926: 301.
Stephensen, 1949: 6.
“Rostrum curved. Sideplate 1 not always exceedingly small. Upper lip incised at narrowed apex. Lower lip with lobes narrowed in front, deeply incised on inner margin. Mandible, cutting edge dentate, accessory plate on left mandible, spine-row well developed, molar process large and protruding, with fluted triturating surface, palp with 3rd joint the longest. Maxilla 1, inner plate very small, outer with 7 ( [ unclear: ] ) spines, palp 2-jointed. Maxilla 2, well developed, inner plate broader than outer. Maxillipeds, inner plates narrow, long, outer reaching beyond 1st joint of rather robust and setose palp. Gnathopods 1 and 2 subchelate. Peraeopods 1-5, uropods 1-3 and telson about as in Amphilochus.”
This diagnosis is taken from Stebbing with the alteration in regard to the process proposed first by Sars in defining the genus and again later by Schellenberg. Stephensen (1949) gives a key to the species of Gitanopsis which includes all species of Amphilochus. Since he refers to G. (Amphilochus) squamosus, it appears that he considers Schellenberg's distinctions only of sub-generic rank. Actually, if this course were followed, Amphilochus has considerable priority over Gitanopsis.*
Two species are here recorded and described, one of these being a new record for New Zealand.
Gitanopsis squamosa (G. M. Thomson), 1880. (Figs. 91-118.)
Amphilochus squamosus G. M. Thomson, 1880: 4, Pl. 1, Figs. 4, 4a. Chilton, 1923: 240. 1923a: 84.
Gitanopsis squamosa Schellenberg, 1926: 301; 1931: 95. Stephensen, 1949: 6, 7.
Gitanopsis antarctica Chevreux, 1913: 104.
“Eyes large, deep red in colour; not easily made out owing to the numerous and dense reddish-black spots with which the whole body is covered” (G. M. Thomson).
[Footnote] * This is a posthumously published paper, and Stephensen himself was not responsible for the final editing.
Antennae. First: Flagellum slightly longer than peduncle, of more than 6 longer-than-wide segments, each with 1 or 2 very long flaccid sensory setae; accessory flagellum of 1 segment arising from 3rd peduncle segment, as long as 1st flagellar segment, slender; 2 setae on end. Peduncle, 2nd segment ¾ length 1st, 3rd ⅔ 2nd, has only very minute bristles. Second: Flagellum longer than peduncle, of 10 segments, all longer than peduncle especially distal ones, a few fine bristle-setae on end margins; peduncle 1st segment ⅔ length 2nd, 2nd as long as 3rd, 1st has spine-seta on superodistal angle, minute teeth on margins, a few fine bristle-setae.
Mouthparts. Upper Lip: Bilobed, symmetrical. Lower Lip: Inner plates absent; outer have a few fine bristles distally, 2 small spines in inner margin distally, a larger incision and spur ½ down margin. First Maxillae: Inner plate small, seta on end. Outer has 7 stout end spines, fine bristles below innermost. Palp of 2 segments, 1st small, 2nd reaching end of outer plate, has 6 or 7 end setae. Second Maxillae: Inner plate has about 11 spine-setae on end margin, outer has 5, is more slender. Mandible: Cutting edge has numerous teeth, spine row of about 8 spines; molar process strong, wide, well-developed; left has accessory plate with several teeth; palp of 3 segments, 1st about ½ length 2nd, 2nd as wide with single seta on inner distal angle, about ¾ length 3rd, which has inwardly curved sharp tip, a few fine bristles on inner margin, a single strong spine with frayed tip about ¾. Maxillipeds: Inner plate almost reaching palp carpus, has thickened end margin, 2 small spines on inner distal surface; outer reaches almost to palp propod, inner margin more or less straight, outer convex, a stout characteristic blade-spine on outer margin near tip, a slender spine inside it, apex of plate slightly produced above both. Palp merus width ½ length, 3 spine-setae on distal ½ of inner margin, 1 distally on outer; carpus barely more than ½ merus in length, slightly narrower, strong tuft of about 8 spine-setae on inner distal angle; propod as long, slightly narrower, 2 spines on outer distal angle, 4 or 5 on inner below dactylos; dactylos a slender spike about ⅔ propod length.
Gnathopods. First: Sideplate subsquarish, anterodistal angle rounded with distinct setal notch, depth about ¾ basos. Basos width ¼ length, 1 or 2 fine setae on posterior margin, several on each of duplicated anterior margins, a few on surface. Ischium ¼ basos, slightly longer than wide, 2 fine setae posteriorly. Merus subrectangular, tending to wedge-shaped, proximal width ½ length, distally ¼ length, length nearly ½ basos, 3 strong spines on almost straight posterior margin, 5 on squarish end which somewhat under-rides carpus. Carpus subtriangular, with squarish lobe posteriorly produced ⅓ to ½ along propod, greatest width barely more than length which is about ⅖ basos; lobe has 5 spines on squarish end, 1 posteriorly a little above, 1 on surface; spine on anterior surface. Propod subrectangular, anterior margin a little convex, 1 and 2 spines on surface anterodistally below dactylos base; palm slightly convex and oblique, finely sawtoothed and merging into straight posterior, 2 strong spines on one surface posterodistally but well below angle, 3 on other; distal width ½ length, proximally narrower; length nearly ¾ basos. Dactylos curved inner margin has strong tooth about 2/3, 12 or so very fine teeth on margin inside this, dactylos quite strong to tip. Second: Sideplate ovate-rectangular, distally rounded margin has 2 or 3 setal notches, anterior and distal surfaces have fine line-like scale markings; width ½ length. Basos about sideplate length; merus has 2 spines on posterior margin, 7 on end of lobe; carpus lobe more slender than in Gn. 1, extending ½ along
Text-fig. 7.—Gitanopsis squamosa (G. M. Thomson). 91, Antenna 92, Antenna 1, accessory flagellum. 93, Antenna 2. 94, Upper lip. 95, Lower lip. 96, Maxilliped, left half. 97, Maxilliped, end of outer plate. 98, Maxilliped, end of palp. 99. Mandible. 100 Mandible, end of palp. 101, Mandible. palp spine. 102, Maxilla 1 103, Maxilla 2. 104. Gnathopod 2. 105, Gnathopod 2, palm and dactylos, 106, Uropod 2. 107, Telson. 108, End of telson.
propod, has spine on outer margin, about 6 on end; otherwise much as Gn. 1. Gill as long as basos, simple and pendulous.
Peraeopods. First: Sideplate subrectangular, angles rounded, width ½ length; small setal notch posterodistally, line-scales along anterior margin. Basos nearly sideplate length, width more than ¼ length, small setae on anterior margin. Ischium subrectangular, width ⅔ length, length ¼ basos. Merus piriform, ½ basos length, width almost ½ length, angles produced, posterodistal one slightly and sharply, anterodistal bluntly and about ¼ along carpus, seta on each and ⅓ down slightly convex anterior margin. Carpus as long, width ¼ length, almost straight posterior margin has 2 small spines, spine on posterodistal angle; propod about ¾ basos length, margins parallel, slightly convex anterior has 4 or 5 bristle-setae, posterior 3 paired-spine interruptions; width about ⅙ length. Stout curved dactylos not ½ propod length, has small spur on inner margin near tip. Second: Generally like 1st except sideplate, which is shallowly excavate to about ⅓ posterior margin, width below that about ⅓ length. Third: Like reverted 2nd but sideplate anterior lobe ovately rounded, posterior slightly deeper, about ¾ basos length, distally somewhat subtriangular. Basos ovate-rectangular, margins subparallel, anterior has about 5 strong short spines on distal ½, posterior smoothly straight, convex only about angles; width about ⅔ length. Merus has 2 pairs of spines anteriorly, slightly produced posterodistal angle. Fourth and Fifth: Like 3rd; basos has about 8 spines anteriorly, 5th a little more expanded, posterior margin more convex with minute bristles.
Epimeral Plates: Damaged; 1st appears ovately-rectangular, 2nd subrectangular with rounded anterodistal angle, blunt posterodistal; 3rd like 2nd but much wider, posterodistal angle rounded, posterior margin straight.
Uropods. First: In bad condition but peduncle appears to have 5 and 8 spines on dorsal margins, rami slender with several spines. Second: Peduncle and inner ramus subequal, peduncle has at least 4 spines on outer margin. Outer ramus [ unclear: ] length inner, finely pectinate inner margin with strong spine near tip, 3 spines on outer; outer ramus has pectinate inner margin, at least 4 or 5 spines dorsally. Third: Missing. Telson: Long, slender, triangular, reaches ½ along outer ramus of uropod 2, has narrow truncate tip with 2 small notches.
Hypotypes: Tray 122/12, Chilton collection, female from Port Chalmers. (This is possibly the type or a paratype).
Localities: Port Chalmers (Tray 122/12); Lyttelton (Tray 13/12; 122/8-10, C1-C3). Antarctic Material: Tray 13/11, shore pools, Scotia Bay, “Scotia,” 2.11.04; Tray 122/7, South Orkney Is., “Scotia” Exped. (this shows 1 or 2 minor differences—e.g., mandibular palp has 2 spines); Tray 143/16, Wilhelmina Bay, 64° 30′ S. 62° W., A. G. Bennett and T. W. B., 8.11.1922.
Discussion. Various authors (e.g., Chilton, Schellenberg) have suggested that Gitanopsis squamosa and Gitanopsis antarctica Chevreux are identical. Barnard (1932: 104) does not accept this as proven because it is based only on Chilton's word, unsupported by drawings or descriptions. The above descriptions and figures should remove any remaining doubts that G. antarctica is a synonym.
Gitanopsis pusilloides Shoemaker, 1942. (Figs. 119-138.)
Shoemaker, 1942: 9-11, Fig. 3.
Stephensen, 1949: 6.
Antennae. First: Peduncle, 1st segment ⅘ length 2nd; 3rd slightly more than ½ 2nd; setae ½ along each margin of 2nd; flagellum of more than 7 segments,
Text-fig. 8. —Gitanopsis squamosa (G. M. Thomson). 109, Gnathopod. 110, Gnathopod 1, side plate posterodistal angle. 111, Gnathopod 1. palm and dactylos. 112, Gnathopod 1, palm and dactylos further enlarged. 113, Peraeopod 1. 114, Peraeopod 2, side-plate. 115, Peraeopod 3. 116, Peraeopod 4. 117, Peraeopod 5. 118, Eprmeral plate 3. Gitanopsis pusilloides Shoemaker, 119, Epimeral plates 2 and 3. 120-122, Uropods 1-3,
accessory of one very small segment or possibly 2, about ¼ length 1st flagellar segment. Second: Like G. squamosus, small tuft of setae ½ along each margin of 2nd and 3rd segment; flagellum of 9 segments.
Mouthparts. Lower Lip: Inner margin not indented, end margin has flattened produced tip, small frayed-tip spine-process immediately below, otherwise margin naked. First Maxillae: Inner plate has 1 end seta, outer has 7 spines, 2 or 3 setae; palp of 2 segments, over-reaching outer plate slightly, end margin rounded, has 2 or 3 spines and 2 setae, inner distal angle a little produced. Second Maxillae: Inner plate, one side has 3 end setae, 1 down inner margin; other has 6 setae along end margin; outer plate has 4 end setae. Mandibles: Palp missing; cutting edges of about 10 teeth, accessory on left of about 12, spine-row of 8-10 spines, molar process a strong wide triturated process. Maxilliped: Inner plate has at least 2 end spines, otherwise difficult to make out; outer has stout end spine, smaller spine-seta inside; inner distal margin finely toothed, 3 setae down margin. Palp merus wide, width ⅗ length, inner margin has 3 short setae on margin near distal angle; outer has 2 small setae medially, 2 and 1 stouter spine-setae near angle. Carpus width ¾ length, length little more than ½ merus, spine-seta ½ along outer margin, about 3 on outer distal angle, 5 on inner. Propod width ½ length, as long as carpus, spine-seta on outer margin about 2/3, 2 at outer distal angle, 6 on inner, 4 thumb-like protuberances below the last; dactylos slightly curved, spike-like, almost propod length, inner margin finely combed.
Gnathopods. First: Sideplate subsquare, angles rounded, seta ⅔ down posterior margin. Basos length about twice that of sideplate, width almost ⅓ length, both anterior margins setose. Ischium subsquare, ¼ basos length, 1 or 2 fine setae posteriorly. Merus ⅓ basos, width about ⅖ length, 2 spine-setae on posterior margin, 5 or 6 on posterodistal angle which is slightly bluntly produced under carpus. Carpus subtriangular, width ½ basos length, nearly twice own anterior margin length since it is produced posterodistally in spoon-like lobe ½ along propod; the lobe has 4 spine-setae on inner margin, 4 on end. Propod ovaterectangular, broadest distally where width about ⅗ length, posterior margin straight, anterior and palm slightly convex, palm defined by 2 stout spines and small notch, is minutely pectinate, pectinations fine but quite long, a few fine setae below palm; dactylos as long as palm, curved, strong tooth on inner margin about ¾, finely pectinate some distance before tooth. Second: Sideplate subrectangular, angles rounded, width ¾ length, several spine-setae on surface. Basos as long, width not quite ⅓ length, minute setae on margins. Ischium subsquare, not ¼ basos length, following segments twisted. Merus subrectangular, width ½ length, length almost ⅓ basos, 1 end spine and 4 or 5 spine-setae. Carpus subtriangular, produced posterodistally in shallow spoon-lobe nearly ½ along propod so anterior margin only about ⅓ length of distal margin, distal ½ basos length. Propod subrectangular, but widening considerably distally to about ⅔ length, as long as basos, margins more or less straight, except slightly posteriorly convex palm, which is finely pectinate, defined by 2 stout spines. Dactylos as long as palm, has strong tooth about ¾ along inner margin, which is finely pectinate previously, the tooth itself pectinate. Gill simple, pendulous.
Peraeopods. First and Second: Like G. squamosa. Third: Sideplate ovate, posterior the deeper, about ¾ basos length. Basos ovate but margins mostly straight, anterior has about 8 spines, 4 setae; posterior naked; width about ¾
Text-fig. 9.—Gitanopsis pusillcides Shoemaker. 123, Antenna 1, accessory flagellum. 124, Lower lip, end of outer plate. 125, Mandible. 126, Maxilla 1, palp. 127, Maxilla 2. 128, Maxilla 2, end of inner plate, other side. 129, Maxilliped, left half. 130, Maxilliped, end of outer plate. 131, Gnathopod 1. 132, Gnathopod 1, palm and dactylos. 133, Gnathopod 1, margin of palm and dactylos. 134, Gnathopod 2. 135, Peraeopod 3. 136, Peraeopod 4. 137, Peraeopod 5. 138, Telson.
length. Fourth: Basos has about 6 spines anteriorly, 3 setae. Fifth: Anterior margin like Pr. 3; posterior a little lobed proximally; almost as wide as long.
Epimeral Plates. Second and Third: Subrectangular, anterodistal angle rounded, posterodistally a little produced in rounded fashion especially 2nd; 4 or 5 setae on ventral margin anterodistally.
Uropods. First: Inner ramus slightly the longer, as long as peduncle, 6 spines on inner margin, 4 on outer; outer has 1 on inner, 5 on outer; 7 on inner margin of peduncle, 10 on outer. No sign of serration. Second: Inner ramus as long as peduncle, outer little more than ½, has 3 spines on outer margin, 1 on minutely pectinate inner; inner has 5 and 4 spines; peduncle has 6 spines on outer margin, 1 on inner. Third: Rami slightly shorter than peduncle, outer about ¾ length inner; has 3 spines on outer margin, 1 medially on inner; inner has 3 on outer margin, 4 on inner; peduncle has about 6 spines on each dorsal margin. Telson: Ovate, smoothly rounded distally.
Localities: Port Chalmers.
Type: Slide Tray 122/11, Chilton Collection.
Distribution: New Zealand; Magdalena Bay, Lower California, U.S.A.
Discussion: This specimen agrees with almost all the details given by Shoemaker for his Gitanopsis pusilloides. There are, however, a few small differences, not very significant in themselves but possibly indicative of other differences which he does not mention.
The carpus of the gnathopods in my specimen has several setae, whereas Shoemaker says it is naked. The palm, as he figures it, is almost at right angles to the posterior margin, and is straight; in mine it is more convex. The number of antennal segments differs; he mentions no accessory flagellum. There is not the same indication of inner lobes to the lower lip. The dactylos in each gnathopod is finely toothed in mine, not naked.
The species is easily distinguished from G. squamosa by the telson. The distribution is rather unusual; for that reason I have detailed differences from Shoemaker's specimens.
The differences from G. pusilla which Shoemaker lists for the spine-teeth of the maxillae do not seem to me as significant as the differences in the gnathopods and also the inner margin of the lower hp, which is incised and has a frayed lobe process in G. pusilla. I suspect variation in the numbers of spine-teeth in the maxillae.
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D. E. Hurley
Portobello Marine Biological Station