AJJD SPECIES OF HYBROIDA. 2G3 



conical process, similar to that which in other Hydroids (Thuiaria) 

 gives attachment to a valve-like operculum. No trace of the 

 operculum was detected in the dried specimens. 



Sertularella episcopus.. Plate XIII. figs. 5-7. 



Syn. Sertulariafusiformis, Hutton in Traus. N. Z. Inst. 1872; Cough- 

 trey in Journ. Otago Inst. 1874. 



Tropliosome. Hydrocaulus attaining a height of about an inch, 

 simple, given off at short intervals from a creeping ramified 

 tubular fibre. Hydrothecse tubiforra, springing from the distal 

 end of the supporting internode, to which they are attached by 

 their fundus, free in the remainder of their height, and strongly 

 diverging from the stem ; orifice deeply cleft above and below, so 

 as to present a mitre-like form, bordered by a thickened margin, 

 below which, on the side facing the internode, there is a thickened 

 involution of the walls of the hydrotheca. 



Gonosome. Gronangia elongated, ovoid, with one wide and shallow, 

 and two narrow and deep longitudinal depressions, which extend 

 from the summit to the base, supported on a short thickish pe- 

 duncle, springing one from each internode at the side opposite 

 to that which carries a hydrotheca. 



Locality. New Zealand, Mr. BusJcs collection. 



Notwithstanding a want of sufiicient exactness in the descrip- 

 tion given by Captain Hutton of his Serttilaria fusiformis, there 

 can, I think, be little doubt that that species is identical with the 

 Sertularella episcopus of the present paper. The name o^fusifor- 

 mis, however, has been already assigned by Hincks to a very dif- 

 ferent British species, and therefore cannot be given to the New- 

 Zealand one. Mr. Coughtrey has iu some points amended 

 Captain Hutton' s description, and has given us a figure of the 

 species. 



The remarkable mitriform and margined hydrothecae of this 

 curious Hydroid at once distinguish it from all other known 

 species. The hydrotheca?, besides diverging from the stem to the 

 right and left, spring more decidedly from one of the remaining 

 two sides than from the other, and are directed at a low angle 

 from the plane of this side. The stem thus presents an anterior 

 (from which the hydrothecfe spring) and a posterior, as well as a 

 right and a left side. The origin of the gonaugia is also somewhat 

 from the anterior side of the internode. 



The specimens formed a dense growth on the surface of a fucoid 



