711 



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

 ridges more equidistant and numerous. 



Found in sandy mud on the coast of Central America. 



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

 Soc. 1835, p. 22. 



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

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

 que decussantibus, undulatis, sublamellosis ; latere antico breviorc, 

 postico subdeclivi ; marginibus depressis ; margine ventrali ro- 

 tundato, intus crenulato." 



The next remove, after Y. subrostrata, from V. cancettata. 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 black ; 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 subimbkicata (pi. cliv. f. 35-38), Sowerby, Pro. 

 Zool. Soc. 1835, p. 21. 



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

 radiata vel variegata; costellis radiantibus confertis, costis subim- 

 bricatis decussantibus, prope umbonem lamelliferis ; latere antico 

 breviore, impressione cordata antica magna; latere postico lon- 

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

 intus denticulate" Variat testa parva, longiore, costis decussan- 

 tibus omnibus lamelliferis. 



A very variable shell, of the same group as V. cancettata, but in 

 which the concentric lamina? 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 Califokniensis (pi. cliv. f. 40, 41), Broderip, 

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



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

 lamellis crassiusculis, lateraliter subcrenulatis, costis crebcrrimis 

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

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

 terno crenato." 



4 z 



