1890.] MARINE MOLLUSCA OF ST. HELENA. 301 



Venus (Chione) pygm.«a, Lamarck. 



Venus pyff7ncea,L?imi\rck, An. s.Vert. ed. 2, vol.vi. p. 337; Haiilev, 

 Cat. Recent Shells, p. 110, pi. 16. fig. 13; Sowerbj, Thes. Coii. 

 vol. ii. p. 707, pi. 156. figs. 69-72 ; Reeve, Cou. Icon. pi. 26. 

 fig. 138 a-^?. 



Hab. West Indies. 



Of this well-defined species I have seen only a single specimen 

 from St. Helena. It is not rayed with pink, as is frequently the 

 case, but merely presents a few brown spots, disposed in rays upon 

 a whitish ground, and a few cross-lines on the excavated hinder 

 dorsal area. 



Cytherea (Caryatis) rudis (Poli). 



Cytherea rudis, PfeiiFer, Conch.-Cab. p. 34, pi. 11. figs. 9, 10. 



Hab. Mediterranean, Adriatic and Black Seas, Canary Islands. 



The shells from St. Helena are rather strongly concentrically 

 sculptured. The largest is 22 millim. in length, and none have a 

 coloured lunule. 



Tellina antonii, Philippi. 



Hab. Guadaloupe, West Indies. 



As far as I can ascertain the above is the only locality quoted for 

 this species. lu the British Museum " East Africa " and " Am- 

 boyna" are attached to some specimens which undoubtedly belong 

 to this species ; but I regard both with suspicion. The three valves 

 from St. Helena are long and narrow, being 55 millim. in length and 

 23 in height. They agree in form with T. cumingii, as figured in 

 Reeve's ' Conchologia Iconica,' fig. 179 «, and, indeed, I question if 

 the limits of that and the present species can be clearly defined. 



The form is subject to considerable variation, even among sj)eci- 

 mens which have identical sculpture, some being much narrower 

 than others. The radiating striae also differ much in development, 

 and although their presence in T. cumingii is not mentioned by 

 Hanley, they have been detected by Romer; and \n all the speci- 

 mens which I have examined their presence, especially in the right 

 valve, is undeniable. T. cumingii has been recorded from the west 

 coast of Central America by Hanley, C. B. Adams, and others, so it 

 may be presumed that that is its true locality, and not the Red Sea, 

 quoted by Sowerby in the ' Conchologia Iconica.' 



Semele cordiformis (Chemnitz). 



Tellina cordiformis, Chemn. Conch.-Cab. vol. xi. figs. 1941-2. 



Amphidesma cordiformis. Reeve, Conch. Icon. pi. 5. fig, 30. 



Hab. West Indies, Georgia, Florida, Brazil, West Africa, West 

 Colombia. 



With this species I unite Aynphidesma orbiculata and A. radiata, 

 both of Say, A. subtruncata, Sowerby, A. reticulata, Soweiijy, A. 

 decussata. Wood, A. luteola, A. Adams, A. lenticularis, Sowerbv 

 andyl. modesta, A. Adams. I believe these so-called species merely 



Proc. Zool. Soc— 1890, No. XXI. 21 



