711 



A more truncated shell than V. caucellata, with the concentric 

 ridges more equidistant and numerous. 



Pound in sandy mud on the coast of Central America. 



22. Venus undatella (pi. cliii. f. 22), Soioerhj, Pro. Zool. 

 Soc. 1835, p. 22. 



"V. testa rotundato-elliptica, crassa, albida, fusco raaculata, 

 punctata, et undatim picta ; costellis radiantibus confertis, aliis- 

 que decussantibus, uudulatis, sublamellosis ; latere antico brcviore, 

 postico subdeclivi; marginibus depressis; margine ventrali ro- 

 tundato, intus crenulato." 



The next remove, after V. suhrostrata, from V. cancellata. It 

 is more broad and truncated, with the dorsal margin less sloping, 

 the edges of the right valve strongly overlapping, that of the 

 left strongly marked with transverse bands of lalack ; the concen- 

 tric ridges numerous, undulated, and crowded near the margin. 



Found on the shore at the island of Tres Marias, Gulf of Cali- 

 fornia. 



23. Venus subimbricata (pi. cliv. f. 35-38), Sowerby, Pro. 

 Zool. Soc. 1835, p. 21. 



"V. testa cordato-subtrigona, crassa, fusco albidoque hneatim 

 radiata vel variegata; costellis radiantibus confertis, costis subim- 

 bricatis decussantibus, prope umbonem lameUiferis ; latere antico 

 breviore, impressione cordata antica magna; latere postico lon- 

 giore, declivi, planulato, depresso; margine ventrali rotundato, 

 intus denticulato.-" Variat testa parva, longiore, costis decussan- 

 tibus omnibus lameUiferis. 



A very vai'iable shell, of the same group as V. cancellata, but in 

 which the concentric laminse are only seen near the umboes, and 

 afterwards exchanged for more or less raised and irregular undu- 

 lations in the same direction. 



Puerto Portrero, Central America. The extreme variety (f. 38), 

 in Mr. Gubba's collection, is from California. 



24. Venus Californiensis (pi. cliv. f. 40, 41), Broderij), 

 Pro. Zool. Soc. 1835, p. 43. V. leucodon, Sowerhij, ib., inclusa. 



"V. testa globosa, crassa, albente, concentrice multilamellosa, 

 lamellis crassiuscuhs, lateraliter subcrenulatis, costis creberrimis 

 cancellata ; area postica infossa, grandi ; lunula magna, tumente ; 

 intus alba, impressionibus muscularibus violaceo-fucatis ; limbo in- 

 terno crenato." 



4 z 



