244 DAVENrORT ACADEMY OF NATURAL SCIENCES 



Family, Mytilid.e, L. 

 Genus, MYTILUS, L. 

 1G2. M. HAMATUS, Say. Attached to oyster shells. 



163. M. EXUSTUS, L. Syn.. M. cubitus. Say. 



164. M. EDULis, L. East coast. 

 Common on both coasts, except the last. 



Genus, MODIOLA, Lam. 



165. M. TLiCATULA, Lam. East coast. 



166. M. SULCATA, Lam. Bahiahonda Key. 



167. M. TULiPA, L. Same locality as the last. 



Genus, DREISSENA, Van Beneden. 



168. D. LEUCOPiiyETA, Con. West coast. 



Genus, LITHODOMUS, Cuvier. 



169. L. ANTiLLARUM, i>'0r6. Taken froui a mass of coral at Tor- 

 tugas. 



Genus, CRENELLA, Brovm. 

 170'. C. LATERALIS, ;S'a(/. (MYTILUS.) From the east coast. 



Family, Arcad^e. 

 Genus, ARCA, L. 



171. A. PEXATA, Say- 



172. A. TRANSVERSA, Say. 



173. A. PONDEROSA, Say. 



174. A. Americana, Gray. 



175. A. No^, L. 



176. A. INCONGRUA, Say. 



Nos. 174 and 176 are peculiar to the east coast, so far as I know. 



Genus, PECTUNCULUS, Lam. 



177. P. PENNACEUS, Con. From the Keys. 



Genus, NUCULA, Lam. 



178. N. PROXiMA, Say. East coast. 



Genus, LEDA, Schumacher. 



171). L. ACUTA, Con. [Nucula.) Am. Marine Conch. This species 



was described as fossil from North Carolina. It has, however, been 



found living there. I also dredged the species alive at Cedar Keys, on 



the Gulf coast in six fathoms of water. This shows a wide distribution. 



Family, Ciiamid^e. 

 Genus, CHAM A. L. 

 180. C. ARCiNELLA. Common around Tortugas. 



