714 



lata ; latere postico declivi, superne planulatim excavato, subtrim- 

 cato; latere antico rotundato ; lunula magna, striata, alba. 



The alternate radiating ribs are more prominent than either the 

 intermediate ones or the radiating stria;, giving a pectinated ap- 

 pearance to the shell. 



America. 



31. Venus asperrima (pi. civ. f. 57, 58), Sowerby, Pro. Zool. 

 Soc. 1835, p. 42. 



"V. testa obovata, crassiuscula, opaca, albicante radiatim costel- 

 lata; costellis numerosis, decussatis, asperis ; latere antico breviore ; 

 margine dorsali postico declivi, rectiusculo; impressione cordiformi 

 anticti elongata." 



Broader, flatter, more truncated posteriorly and more sharply 

 ribbed and decussated than V. pectorina. 



In fine sand at low water ; at the island of Lobos, Peru. Cuming. 



32. Venus histrionica (pi. civ. f. 52), Soiverby, Pro. Zool. 

 Soc. 1835, p. 41. 



" V. testa obovata, pallide fulva, radiatim costellata, costellis 

 plerumque duplicatis, concirme decussatis, asperis, maculis inter- 

 rupts fuscis irregularibus radiatim picta ; margine dorsali rectius- 

 culo, postice subangulato ; impressione cordiformi antica parva, 

 intus purpurascente ; margine ventrali denticulato." 



More rounded and flatter than V. pectorina, with the ribs more 

 equal, duplicate and rounded ; the markings consist of several rays 

 of fantastically-shaped patches of brown. 



Pound in sandy mud at a depth of thirteen fathoms, at Guaco- 

 mayo, Central America. Cuming. 



33. Venus intersecta (pi. civ. f. 59, 60), Sowerby, jun. 



V. testa ovali, ventricosa, alba vel grisea, fusco-cinerascente 

 omnino picta vel postice maculata, intus alba, costelbs acutiuscu- 

 lis tripartitis radiata, striis elevatis concentricis intersecta ; latere 

 postico subdeclivi, subacuminato ; area dorsali angusta, excavata, 

 valvse dextrse fusco-albo maculata, valvse sinistra fusco nigres- 

 cente ; latere antico breviusculo, rotundato ; lunula fusca, radiatim 

 striata ; dente cardinali antico permagno. 



In texture nearly resembling V. pectorina ; in shape approach- 

 ing V. crenifera, yet larger and less pointed than that species. 

 In the specimens I have seen, the dorsal area of the right valve is 



