On Hydroida from Kerguelen's Island. 113 



ambulacralibus, his numero duabus supra scutum teitium, qiiartum, 

 aliquando quiutum, unica supra cetera, et supra quimque 

 marginem pori ambulacralis primi (infrabrachialis) papillis 4-5. 

 Color albidus. 

 Disci diam. 9 milUm. 



Hah. Swain's Bay. 



The spines on the rays are very small, and similar to 

 those described by Ljungman as existing in 0. Lymani, 

 which cannot be confounded Avith the present species, as it 

 differs in size, length of the arms, form and size of the radial 

 shields, &c. 



XII. — Descriptions of some new SiJecies of Hydroida from 

 Kerguelen''s Island. By Professor Allman, M.D., LL.D., 

 F.R.S., P.L.S. 



Seven species of Hydroida were collected recently in Ker- 

 guelen's Island while the English Transit Expedition was 

 there. They comprise one representative of the Gyranoblastic 

 and six of the Calyptoblastic hydroids. None of them has 

 been previously described ; and one is the type of a new genus. 

 I reserve figures and full particulars respecting them for 

 my formal report upon the collection, giving merely short 

 descriptions of them here. 



Hydroida Calyptoblastea. 



Genus Sertularella, Gray. 

 Sertularella kerguelenensts, n. sp. 



Trojyhosoyne. Hydrocaulus about an inch in height, much 

 and irregularly branched, monosiphonic ; intemodes with 

 shallow annulations at their proximal ends. Hydrothecte 

 springing each from an internode close to its distal end, some- 

 what tumid below, tapering towards the summit, which is 

 slightly incurved towards the stem ; orifice with four distinct 

 teeth. 



Gonosome. Gonangia springing each from a ])oint just below 

 a hydrothcca, subsessile, ovoid, with a short tubular 4-toothed 

 summit, annulated, the annulations becoming obsolete towards 

 the base. 



Hab. Swain's Bay (Eaton). 



Nearly allied to S. polyzonias. 



