1890.] MARINE MOLLTJSCA OF ASCENSION ISLAND. 321 



figured by Kiener (Coq. Viv. pi. 6), but the tubercles are rather 

 larger and more obtuse. 



Nerita ascensionis, Gmelin. 



Hah. Ascension Island ( Quoy Sf Gaimard, Trimen, Conry, Chem- 

 nitz, &c.) ; Island of Trinidad, off Brazil, and Fernando Noronha. 



Basilissa oxytropis, Watson. 



Basilissa oxytropis, Watson, Report ' Challenger ' Gasteropoda, 

 p. 104, pi. vii. iSg. 9. 

 Hah. Ascension Island, 420 fathoms. 



FrssuRELLA NUBECULA (Linn^). 



Hab. Mediterranean, Morocco, Cape Verde Islands, Senegambia, 

 Guinea. 



With this species, besides F. rosea, Lamarck, should be united 

 F. ostrina, Reeve, described without locality. 



WiLLIAMIA GUSSONII (Costa). 



This species is also found at St. Helena, and has already been 

 noticed and references given in the preceding report on the Mollusca 

 of that Island. 



Utriculus oryctus, Watson. 



Utriculus oryctus, Watson, Report ' Challenger ' Gasteropoda, 

 p. 653, pi. xlviii. fig. 12. 



Had. Ascension Island, 420 fathoms. 



Cylichna cylindracea (Pennant). 



Hab. Ascension Island (' Challenger' Exped.). 



Haminea hydatis (Linne). 

 Hab. Ascension Island {li. Trimen). 



The specimens from Ascension, like those referred to from St. 

 Helena, are all small, none exceeding 10 millim. in length. 



Dentalium entalis, var. agile. 



Hab. Ascension Island, 420 fathoms (' Challenger ') ; North Seii, 

 Bay of Biscay, Mediterranean, Azores, Canaries, Gulf of Mexico. 



II. PELECYPODA. 



Semele cordiformis (Chemnitz). 

 Hnb. Ascension (Conry). 



Remarks on the distribution and synonymy of this species are 

 given in the St. Helena Report. 



LuciNA (Codakia) imbricatula, C. B. Adams. 



Hab. Ascension {Conry and R. Trimen'). 



This species is scarcely distinguishable from L, pecten, Lamarck. 

 The latter is rather more finely sculptured. Both forms occur at 

 St. Vincent's, West Indies. 



