190 CAMPANULINID^E. 



culars : Its calycle is " crowned by long converging seg- 

 ments, which on the retreat of the polypite form a true 

 operculum," while in C. acuminata it is merely " continued 

 by a delicate, collapsile, and undivided membrane ; " the 

 web that unites the bases of the tentacles is much more 

 slightly developed ; and the gonozooid has four tentacles, 

 instead of two, at the time of its escape from the capsule. 

 Hob. Investing the surface of Sertularian Hydroids 

 from about 5 fathoms in the Firth of Forth (G. J. A.). 



3. C. TURRITA. 

 Plate XXXVI. fig. 2. 



STEM distinctly ringed throughout, somewhat zigzagged, 

 bearing short, annulated ramules in groups of two or 

 three at every bend, each of them supporting a polypite ; 

 HYDROTHEC^E tall and slender, widening gradually up- 

 wards from the base, with an operculum composed of 

 short, convergent segments ; GONOTHEC JE broad and sub- 

 truncate above, bulging slightly at one side, tapering 

 downwards, shortly stalked, and borne on the stem. 



GONOZOOID closely resembling that of C. acuminata. 



I AM only able to give an imperfect account of this very 

 pretty species, as I have not had the opportunity of ex- 

 amining specimens. It differs notably from C. repens in 

 the shape of the calycles. The segments composing the 

 operculum are very much shorter in proportion to the 

 length of the hydrotheca than in the latter species. In 

 C. repens they are deep and form a tall, acuminate 

 covering, which is about a third as long as the calycle ; in 

 C. turrit a the striking feature is the disproportion between 

 the latter and the shallow operculum. The general habit 

 and the grouping of the ramules also differ in the two 

 forms. 



