240 



SERTULARIID^E. 



Fig. 30. 



much branched; sometimes the stems divide dichoto- 

 mously, and frequently terminate in a fork. The calycles 

 are narrow and cylindrical not swollen at the base. The 

 rim of the aperture rises into three strong denticles, the 

 largest in front, and the others on the sides. The margin 

 is somewhat thickened. 



The capsules, which are very large in proportion to the 

 size of the calycles, are less inflated than 

 those of polyzonias, and much more 

 strongly ribbed transversely. The sides 

 are cut into deep dentations between the 

 rings, which extend uniformly from top 

 to bottom. At the upper extremity 

 the capsule expands into a kind of 

 bowl, and from the centre of this rises 

 a narrow funnel-shaped aperture with a 

 plain rim. 



S. tricuspidata has only been found 

 in the north. Amongst some dredgings, 

 obtained in 100 fathoms, near Reikiavik, in Iceland, it 

 occurs in great abundance and of unusual size. The spe- 

 cimens from this locality bear the reproductive capsules 

 in profusion, their branches being frequently laden with 

 them throughout their whole extent. They were taken 

 up amongst "icebergs, grounded and drifting." It is 

 probably this species which Mr. Busk has figured in the 

 ' Microscopical Journal/ from a specimen procured in 

 Greenland, under the name of S. polyzonias. 



Hab. Parasitical on other zoophytes, "from the deep- 

 water boats that supply Newcastle market with fish during 

 the spring months ; not rare" (J. A.). 



[Off Reikiavik, Iceland (T. II.): Greenland (Busk): 

 Straits of Belle Isle, in 40 fathoms, abundant (A. S. 

 Packard, jun.) .] 



