Art. XXXV.—Critical Notes on the New Zealand Hydroida.
[Read before the Otago Institute, October 26, 1875.]
To the last volume (No. VII.) of the “Transactions,” I contributed a paper on the “New Zealand Hydroida,” in which I gave the results of an examination of the type specimens of Capt. F. W. Hutton's paper on the New Zealand Sertularians,” * and of several other specimens I had obtained on the New Zealand coast. Further study of these species and comparison of them with British and other forms have proved to me that in many cases I was in error in my previous paper, and I now hasten to correct these errors. The classification I have now adopted is the commonly accepted one of Mr. Hincks, as proposed in his “British Hydroid Zoophytes,” and the order will, therefore, be found different to that used in my former paper. Mr. Hincks divides the Hydroida proper into three sub-orders: α Athecata (Hydroida destitute of true thecæ, or protective cases either for the polypites or gonophores; β. Thecaphora (Hydroida furnished with thecæ), and γ. Gymnochroa (Hydroida destitute of polypary). The first of these corresponds with Professor Allman's Gymno-blastea, and is represented in New Zealand by the Eudendridœ and Tubularidœ † more especially the second agrees with
[Footnote] * Vol. V., 1872.
[Footnote] † I append to these notes a description of a pretty Tubularian species I Iately obtained in the Rock-pools off Tomahawk Caves, and in various parts of the Upper Harbour, Dunedin.
Allman's Calypto-blastea, and is very abundantly illustrated on our coasts; the third sub-order is identical with the Eleuthero-blastea of Allman, some members of this sub-order also existing in New Zealand. ‡ §
Sub-order Thecaphora, Hincks.
Family I.—Campanularidœ. Genus Obelia.
O. geniculata, Linnæus, Hincks, loc. cit., p. 148.
Laomedea-geniculata, vide “Trans. N.Z. Inst.,” Vol. VII., p. 290, Fig. 42, Pl. XX.
It differs from the British specimens in the following particulars. It is more robust in habit, its hydrothecæ are larger, and its gonothecæ present some peculiarities; in many specimens these are decidedly urceolate, but occasionally there occurs on the same colony one or two reproductive capsules that have a similar form to the nutritive calycles, only that they are quite as large as the other gonothecæ. For interesting points concerning its distribution in space, I must refer to the “Annals and Magazine of Natural History.”
O. pygmœa, sp. nov., mihi. Vide “Annals” loc. cit.
C. bilabiata, mihi. “Trans. N.Z. Inst.,” Vol. VII., p. 291, Figs. 46–49, Pl. XX.
This not like any of the British formus.
C. Integra, Hutton, Vol. VII., “Trans.” loc. cit.
The species I depicted in Fig. 45, Pl. XX., I now believe to be Campanularia caliculata, Hincks.
Family IV.—Lafoëidœ. Genus Laföëa, Laniouroux.
Within the past four months I have got several scraps of what I believe to be Lafoëa dumosa, chiefly from Wickliff Bay, Hooper's Inlet, and Sandfly Bay Beach, Tairoa Peninsula.
Family VII.—Haleciidœ. Genus Halecium, Oken.
H. delicatula, sp. nov., mihi. “Annals,” loc. cit.
I have since obtained this in the lower harbour Port Chalmers.
Family VIII.—Sertulariidœ. Genus Sertularella. *
S. johnstonii, Gray, “Dieff. N.Z.” Hutton, loc. cit. Coughtrey, “Trans,” loc. cit.
[Footnote] ‡ Vide Memoir on Tubularian Hydroids. Roy. Soc., 1871.
[Footnote] § I have seen two Hydrœ in New Zealand; one nearly like H. viridis, of Britain, and the other I have not been able to identify with the British members of Gymnochroa.
[Footnote] * Genus Sertularia is now divided into three:—1. Sertularella; 2. Diphasia; 3. Sertularia.
Though larger in general habit, and the hydrothecæ are more of a subconical form than what we find in S. tricuspidata, I agree with Mr. Hincks that the two species are very closely allied to one another.
S. simplœ. Hutton, loc. cit. Coughtrey, “Trans.,” loc. cit., p. 283. Figs 8 to 11, Pl. XX.
In my paper to the New Zealand Institute, I expressed an opinion that S. simplœ of Hutton was the New Zealand representative of S. polyzonias of Linnæus, and I grouped along with Hutton's species, several pigmy varieties in which the hydrothecæ were transversely wrinkled. In this I was wrong, and I would now regard Captain Hutton's species as a distinct one, approaching nearest to Sertularella fusiformis of Hincks, while the transversely wrinkled variety is an intermediate form between S. rugosa and S. tenella (British species), but resembling more closely the latter, and the large form (“Trans.,” loc. cit., Fig. 10, Pl. XX.), I have proposed to call Sertularella robusta. Vide “Annals,” loc. cit.
Genus Sertularia, Linnæus (in part.) Hincks, “Brit. Hyd. Zooph.”
S. bispinosa, Gray.
Mr. Busk when reporting on the Sertularian Zoophytes and Polyzoa of South Africa (“Brit. Assoc. Reports,” 1850), remarked upon the resemblance between this species and S. operculata (British.) The likeness only holds good between one of the varieties of S. bisinosa, of New Zealand, and that is the extremely lax, slender and delicate variety. The other variety both by the peculiarity of its gonothecæ, and its more robust and coarse habit is different from the British form.
S. ramulosa, mihi. Trans., loc. cit. There are two varieties, coarse and delicate.
S. trispinosa, mihi. Trans. loc. cit.
The intermediate position of this species between S. bispinosa and S. ramulosa, has been preserved in all recent specimens.
S. abietinoides. Gray.
One variety of this species bears a close resemblance to S. filicula (British species) in its general habit, but the characters of the hydrothecæ and of the gonothecæ are quite distinct. Similar differences separate it from the more robust British ally S. abietina.
S. fusiformis, Hutton, loc. cit. Coughtrey, p. 285 (Trans. loc. cit.)
In consequence of there being a likelihood of this species being confused with Sertularella fusiformis, of Hincks, I would suggest for this species the name of Sertularia longicosta (from the crest along one side of the gonothecæ.) Its ovarian capsules, approach somewhat the form of those described by Mr. Busk, on the South African variety of Pl. cristata, again the apex of the capsule has an appearance not unlike the crest of Camp.
calceolifera, Hincks. “Annals N.H.,” Ser. 4, Vol. X., p. 85. It never attains a greater height than two inches.
Sertularia pumila (sp. nov. to N.Z.), Synthecium gracilis, mihi, “Trans.” loc. cit., p. 286, Figs 26 to 31, Pl. XX.
I am now perfectly satisfied that I was in error when I placed this species under Allman's genus Synthecium. I have carefully compared it with varieties of S. pumila from the Mersey (Britain) and elsewhere, and cannot detect sufficient specific characters for a new species. The difference I observed in the New Zealand specimens as shown in Trans. loc. cit., Pl. XX., Figs 26 and 27 (both magnified to same extent) is present in British specimens, and one character has been observed by Dr. M'Intosh, in St. Andrew's specimens (namely, presence or absence of joint in the stem). “Annals N. H.,” Ser. 4, Vol. XII., p. 205.
Sertularia elegans. Synthecium elegans, Allmans. (Gymnoblastic Hydroids).
Another small specimen has enabled me to confirm my previous identification of this species. It is equally pigmy in size with my first one, and in one of the calycles has the lower three-fourths of the pecular ovarian capsules described by Professor Allman. *
Sertularia monilifera, Hutton. Coughtrey, “Trans.,” loc. cit., p. 282.
I am now inclined to place this species under the genus Diphasia.
Genus Hydralmania, Hincks.
During my two visits to the Bluff Harbour, I obtained a most beautiful Hydroid, which I have provisionally placed under the above genus with the specific name of bi-calycula. The description of H. bi-calycula is given in the communication to the “Annals” before alluded to.
T. sub-articulata. I am now quite satisfied that this species is distinct from the British species T. articulata. T. articulata is by far the finer and more delicate of the two, its pinnæ are longer, the hydrothecæ more evenly tubular and free from dentations, while the absence of transverse wrinkles over the whole of the ovarian capsules contrasts clearly with the New Zealand form. Though some of the British specimens have the proximal three-fourths of the ovarian capsules wrinkled.
Our Southern specimens bear the same relation to the East Coast ones, as Mr. Norman's Shetland variety, bears to the ordinary British form.
Regarding the members of the family Plumularidœ, I desire to reserve my notes with one exception, and that is Plumularia simplex, mihi. Fresh
[Footnote] * In Annals loc. cit., I describe a specimen from the Bluff Harbour that is very like S. pumila.
specimens of this have proved to me it is not a Plumularian, but a Sertularian, and I intend to place it in its proper position in a future paper.
Description of a New Zealand Tubularian (Family Tubularidæ.)
“Hydrocaulis developed, invested by a chitinous perisarc. Hydranths flask-shaped, with a proximal and a distal set of verticillate filiform tentacles. Gonophores in the form of fixed sporosac.” (Hincks and Allman).
Genus Tubularia. Sub-genus Thamnocnidia, Agassiz.
Tubularia attennoides, sp. nov.
Trophosome. Hydrocaulis of a cluster of simple stems, semitortuous, of about ½ line in width and from one to two inches in height; perisarc strong and leathery, corrugated transversely in the distal part of stem so as in some places to closely resemble annulations; perisarc for a line in length from base of hydranth is very transparent and delicately annulated just beneath the collar.
Hydranth separated from stem by a distinct but simple (unfluted) collar, which becomes narrow near the base of the hydranth; proximal row of tentacles, about twenty-four in number, and about double the length of inner or distal row, which are about twenty in number.
Gonosome, Gonophores male, on very short erect peduncles, from two to six in one cluster; when two, sub-pedunculate; when six, nearly sessile. Each gonophore has four tentaculi-form processes which are more delicate than those seen in T. attenuata, Allman, and relatively much longer. Colourbody of hydranth, a bright orange-vermillion, darkest within the inner circle of tentacles; cænosarc, dusky vermillion; perisarc, straw colour; spadix, true vermillion.
Attached to sides of rock-pools and submerged piles at Anderson's Bay, Vauxhall Jetty, and other places in Dunedin, Upper Harbour, rock-pools in Tomahawk and other bays between Hooper's Inlet and Ocean Beach, Otago Peninsula.