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Volume 73, 1943-44
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The Genus Adaeum Karsch (= Algidia Hogg) in New Zealand, With Descriptions of New Species (Order Opiliones).

[Read before Wellington Branch, October 12, 1942; received by the Editor, November 11; 1942; issued separately, June, 1943.]

The Opiliones constitute one of the numerous orders of the class Arachnida. They are commonly referred to as Harvestmen or Harvest Spiders, but differ from true spiders in the absence of a constriction between the cephalo-thorax and the abdomen. They can be easily distinguished from the closely-related group of Mites by the occurrence of segmentation on the abdomen.

Usually, the eyes are situated on a mound arising from the cephalo-thorax, the position and shape of this mound being of extreme importance in the classification of the majority of these arachnids. At present there are about thirty species recorded from New Zealand. With the exception of one paper published by Grimmett and Phillips (Proc. Zool. Soc., 1932), all the species have been described by overseas arachnologists from specimens forwarded to them by New Zealand collectors. Accordingly, as yet nothing is Known of their life histories and habits; and no doubt many interesting facts await discovery by New Zealand arachnologists.

Opiliones are to be found almost anywhere, the most profitable localities being under and in dead logs and in the debris of the forest floor. It is not uncommon to find specimens of four different genera under one log.

Indications point to the occurrence of a very extensive Opilione fauna in New Zealand, and this paper will be the first of a series of papers on the New Zealand Opiliones.

The genus Algidia was erected by Hogg in 1920 (Proc. Zool. Soc., 1920, p. 46) for the reception of his species Algidia cuspidata, but this genus agrees in every character with the genus Adaeum Karsch, which was erected by Karsch in 1880 (Zeit. Naturw., v. 53, p. 403). Therefore the genus Algidia Hogg must be sunk as a synonym of the genus Adaeum Karsch. Hogg had five specimens of which three were males, two being from Mt. Algidus and the other from the Remarkables, Lake Wakatipu, Otago. The remaining two specimens were females, one from Mt. Starve-all, near Nelson, and one from Canterbury. The exact locality of this latter specimen is not given. From this it can be seen that his male and female specimens were collected from widely-separated districts. Although these male and female forms were considerably different in structure, Hogg considered that because of their similar colouration they constituted one species. I find, however, that what were considered by Hogg as sexual characters are in truth specific characters. Extensive collections made from a number of localities have yielded a series of females corresponding to his male form and a number of males corresponding to his

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female form, showing that what he regarded as being one species more correctly should be divided into two species. Further proof of this is afforded by the fact that on a number of occasions I have collected pairs of males and females in close association for each species. On no occasion have I collected the two forms described by Hogg associated together.

The male form of Hogg's Algidia cuspidata was described by Loman in 1902 under the name of Adaeum nigriflavum, under which name it must remain. The female form belongs to a new species for which I propose the name Adaeum hoggi n. sp.

Adaeum nigriflavum Loman. Plate 9, figs. 46.

  • Adaeum nigriflavum Loman, 1902.

  • " " Roewer, 1914.

  • Algidia cuspidata Hogg, 1920.

  • Adaeum nigriflavum Roewer, 1923.

Colour: Generally an ochreous yellow, with two black bands extending from the anterior corners of the carapace to the free abdominal segments. The margin of the posterior abdominal segment of the carapace and the terga of the free abdominal segments have each a yellow border. The remainder of the exposed surface of the free abdominal terga is coloured black. The lateral marginal area of the carapace is light-yellow, broadening in the centre and tapering anteriorly and posteriorly. This band of yellow gives the species at first sight a very constricted appearance. The area between the two black bands is darker than is the marginal yellow band. There are several scattered blackish areas in this region.

Carapace: Forming a design on the carapace are five transverse double rows of small yellow tubercles. These lines are terminated by two longitudinal lines of tubercles situated in the black bands. There are four rows of spinous tubercles on the abdominal segments. The tubercles of the first three rows each arise from a round yellowish patch. There are two pairs of similar spines, one pair on each of the last two abdominal segments of the carapace. On the anterior margin of the carapace are seven strong spines. Behind each anterior corner is a bunch of three small spines.

Genital Operculum: On the margin and including one pair immediately behind the margin of the genital operculum is a row of from 10–12 tubercles each terminating in a short bristle.

Mouth Parts: The mandibles are short and weak. The palp strongly spined, about the length of the carapace. Male palp is much stouter than that of the female.

Eye Mound: Hemispherical, with a median row of tubercles, from 2–4 in the male and three in the female. The carapace immediately around the eye mound of the male is swollen into a secondary mound.

Legs: The trochanters of the legs and the intervals between are strongly spined. The legs have denticulations, with a short bristle on each, as far as the distal end of the tibial joint. The metatarsal segments smooth, the tarsi with short hairs. Tarsal claws of Legs III and IV with short side claws. On the ventral surface the coxae all are bordered by rows of warty prominences, the front margin of coxa I having a row of sharp-pointed black spines.

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Measurements: Leg I 5 mm.
" " II 9.4 " "
" " III 7 " "
" " IV 10.6 " "
Palp 3.7 " "
Mandible 1.2 " "
Carapace 3.3 " "

Locality: Collected Karori; Days Bay, where it is common. (Author's Coll.).

[The section below cannot be correctly rendered as it contains complex formatting. See the image of the page for a more accurate rendering.]

Plesiotype: Tube 2/2 Dominion Museum Spirit Collection.

Adaeum hoggi n. sp. Plate 9, figs. 13.

Colour: Same as in A. nigriflavum.

Carapace: Carapace nearly parallel-sided. The tubercles on the abdominal segments are more numerous than in A. nigriflavum. There are three pairs of spines on the abdominal portion of the carapace. The anterior margin of the carapace is armed with five strong spines. The legs and coxae are spined as in nigriflavum.

Genital Operculum: The margin of the operculum is divided into 7–10 tubercles which do not terminate in a bristle as in A. nigriflavum.

Mouth Parts: Palp slightly longer than carapace. Mandibles short and weak.

Eye Mound: Hemispherical, with a median row of from 4–6 tubercles in the male and 4–7 in the female.

Measurements: Leg I 5.4 mm.
" " II 8.5 " "
" " III 7.0 " "
" " IV 9.8 " "
Palp 4.3 " "
Mandible 1.9 " "
Carapace 3.4 " "

[The section below cannot be correctly rendered as it contains complex formatting. See the image of the page for a more accurate rendering.]

Type: Tube 1/1 Dominion Museum Spirit Collection.

Locality: This species I have found common at Dannevirke (type locality), Feilding, Rimutaka District, and Te Mata Park, Hawke's Bay, under stones and logs. When disturbed, this species, in common with A. nigriflavum, remains rigid. Even if picked up by one leg they show no signs of life. At times I have examined the undersurface of logs and stones very minutely for small insects, and have failed to see specimens reposing among the debris-until they moved and thus caught the eye.

Adaeum bilineatum n. sp. Plate 10, figs. 710.

Colour: Dorsal surface and legs are a uniform yellow-brown except for a short band of darker brown on each side of the carapace originating above coxa III and fading out at the posterior edge of the carapace. Under-surface a darker brown. Each tergite with a transverse row of yellow spots placed in a black band. From each of these spots arises a small seta.

Carapace: Surface is ornamented with two lines of prominent spines arranged in five pairs, the fourth pair being the largest. The lines start at a point immediately behind the eye mound, and half

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way between it and the lateral margin of the carapace. There is a design in the form of rows of closely-placed small warty pustules on the carapace. There are several more small spines. Bordering the anterior edge of the carapace and extending about one-quarter along the lateral margin is a row of nine large marginal and two submarginal spines. There is another spine halfway along each lateral margin and also one on each of the inner anterior margins of the brown bands. Abdominal area V and the three free terga each with a transverse row of strong spines extending over the whole width of the dorsal area.

Genital Operculum: Covered with 12–14 setaceous pustules which, however, do not form a margin as in the other species of this genus. Each of these tubercles give rise to a long curved seta.

Mouth Parts: The coxa of mandibles and palp smooth, with one spine on the outer anterior ventral surface of the coxa of the palp. Palp strongly spined. Mandibles: First segment with several small tubercles on the distal surface; second segment bears a number of scattered pustules from which emanate long setae.

Eye Mound: The colour is yellow with a black area around the eyes, the latter being yellow. Along the median line of the eye mound are placed two large tubercles, one anterior dorsal in position, the other posterior dorsal. The tubercles are each as high as the mound.

Legs: All the trochanteral, femoral, and tibial joints are sparsely spined, metatarsus with four evenly-spaced longitudinal rows of bristles which distally are obscured by a thick covering of fine hairs, The. clothing of fine hairs is continued over the tarsi. The tarsal segments number 3, 8, 4, 4, from Leg I to IV. Claws of Legs III and IV each give rise to small side claws.

Measurements: Leg I 8.6 mm.
" " II 20 " "
" " III 14.9 " "
" " IV 19.7 " "
Palp 5.4 " "
Mandible 2.0 " "
Carapace 5.1 " "

Locality: Collected by E. Fairburn at Mair Park, Whangarei (type locality).

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Type: Tube 2/3 Dominion Museum Spirit Collection.

Remarks: This species is distinct from the other species in size and colour and at a glance can be seen to be much more profusely spined. I have examined a large number of specimens, and can find no distinct sexual characteristics.

Adaeum fairburni n. sp. Plate 10, figs. 1114.

Colour: General colour a light brownish-yellow. There are two black patches placed one in each posterior corner of the cephalothorax. There is a well-defined line along the suture between the cephalo-thorax and the first abdominal segment of the carapace. The legs are ringed by areas of a darker brown than the rest of the dorsal surface. Ventral surface-uniform brown, darker than the dorsal surface.

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Carapace: There is a prominent black spine in the median line on the posterior edge of the carapace. There is a row of seven spines on the anterior margin of the carapace, and two more on a submarginal ledge, which continues along the lateral margin of the carapace to the posterior corner on each side. There is a bunch of three spines below each anterior corner of the carapace. On the dark patches there are three more spines, a pair on the anterior margin, and a single spine on the posterior margin. There are three pairs of spines on the abdominal segments of the carapace. There are four transverse rows of spines on the abdominal portion of the body. The first row of spines, situated on the posterior margin of the carapace, is very inconspicuous owing to the small size of the spines and their yellow colouring matching the general body colour.

Genital Operculum: Genital operculum with a row of five yellow spinous tubercles near the anterior margin.

Mouth Parts: Mandibles weak, botli segments with several small scattered tubercles on the dorsal surface. Palp strongly spined.

Eye Mound: General colour black, with a median row of three yellow tubercles about three-quarters the height of the eye mound.

Legs: Ventral surface of coxa I with a number of spinous pustules on the anterior margin. Ventral surfaces of coxae II, III, and IV smooth except for a row of small yellow processes on each margin. Trochanteral, femoral, and tibial segments have several longitudinal rows of small bristles. Tarsi sparsely covered with short hairs. Tarsal segments 3, 5, 4, 4.

Measurements: Leg I 4.3 mm.
" " II 8.5 " "
" " III 7.4 " "
" " IV 8.0 " "
Palp 2.9 " "
Mandibles 1.1 " "
Carapace 2.7 " "

Localities: Collected Hikurangi Swamp, under logs; Karo Forest, at Whangarei (type locality) by E. Fairburn, after whom I have much pleasure in naming the species.

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Type: Tube 2/4 Dominion Museum Spirit Collection.

I wish to acknowledge my appreciation of the guidance given, me by Mr. J. T. Salmon, Entomologist of the Dominion Museum, during the preparation of this paper.

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Figs. 1–3: Adaeum hoggi n.sp. 1—Carapace. 2—l'alp. 3—Genital operculum.
Figs. 4–6: Adaeum ngriflaum Loman. 4—Carapace. 5—Palp. 6—Genital operculum.

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Figs. 7–10 Adacum n sp. 7—Carapace. 8—Palp. 9—Gential of erculum 10—Protile view of carapace showing eye tubreles
Figs. 11–14: Adacum n.sp. 11—Carapace. 12—Palp. 13—Genital operatium. 14—Side view of the carapace showing e.c tuberele.