252 [February, 



Unio lugubris, Lea, vi. 30, 9, 25, Synopsis, 38. 

 Chemt, Conchyl. Unio, pi. 20, fig. 3. 



maculatus, Con. New Fresh Water Shells, May, 1834, 30, 4, 4. 

 Lea, Synopsis, 24. 

 U. Ravenelianus, Lea, Aug. 1834, v. 32, 3, 5. 



Masoni, Con. Monog. 28, 12, 2. 

 Lea, Synopsis, 34. 

 Kust. Chem. Unio, pi. 5, fig. 6. 



mcestus. Lea, 1841, viii. 244, 26, 60. Synopsis, 31. 

 Clieiiu, Conchyl. Unio, pi. 28, fig. 3. 



merus, Lea, 1852, x. 260, 15, 10. Synopsis, 33. 



Menkianus, Lea, 1838, vi. 76, 19, 59, Synopsis, 27. 

 Chenii, Conchyl. Unio, pi. 19, fig. 4. 



Metallicus, Say, Dissem. 1830. 



Amer. Conch. Synonym, of Unio, No. 51. 

 U. cuprinus. Lea, 1834, iv. 94, 12, 24. Synopsis, 38. 

 Chenu, Conchyl. Unio, pi. 11, fig. 3. 



metanever, Raf. Ann. v. 39. Poulson's Trans. 39. 

 Fer., Guerin's Mag. 1835, 27. 



U. metanevrus, Say^ Amer. Conch. Synonym, of Unio, 24. 

 Con., Monog. 10, 5, 2. 

 Kusl. Chemn. Unio, pi. 10, fig. 4. 

 U. nodosus, Barnes, Sillim. Journ. vi. 124, 6, 7. 

 U. rugosus, (?) ib. ib. vi. 126, 8, 9. 



U. metanever, Lea, Synopsis, 22. 



minor, Lea, 1846, ix. 276, 39, 2. Synopsis, 31. 



Mississipiensis, Co?^., Journ. Acad. Nat. Sc. ii. 277, 38, 11. 

 Lea, Synopsis, 29. 



Mortoni, Con., Monog. Dec. 1835, 11, 6, 1. 

 Kust. Chemn. Conchyl. Unio, pi. 11. fig. 1. 

 U. turgidus, Lea, 1837, vi. 11, 5, 11. 

 Chenu, Conchyl. Unio, pi. 25, fig. 1. 



Miihlfeldianus, Lea, 1838, vi. 41, 12, 36. Synopsis, 30. 

 Cheiiu, Conchyl. Unio, pi. 17, fig. 5. 



Monroensis, Lea, 1841, ix. 279, 41, 8. Synopsis, 29. 



Moussianus, Lea, 1852, x. 268, 18, 22. Synopsis, 29. 



Nashvillianus, Lea, 1834, v. 100, 14, 43. Synopsis, 29. 



nasutus. Say, Nicholson's Ency. article Conch, pi. 4, fig. 1. 

 ListerKi Conch., t. 151, fig. 6. 

 Con. Monog. 38, 18, 1. 

 Gould, Invert, of Mass. 109. 

 Dekay, Zool. of New York, 191, 20, 239. 

 Lea, Synopsis, 37. 



Mya nasuta, Wood., Index Test. Sup. pi. 1, fig. 4. 

 U. rostratus, Valenc Humb. and Bonpl., ii. 223, 53, 3. 

 Eurinea nasuta, Agas. Stlmpson's Shells of New England, 13. 



nebulosus. Con. New Fresh Water Shells, 28, 3, 7. 



neglectus, Lea, 1846, ix. 280,42, 10. Synopsis, 33. 



nexus, Say, Transyl. Journ. 1831, fv. 527. 

 Amer. Conch, pi. 51. 

 Con. Monog. 68, 38, 1. 

 Fer. Guerin's Mag. 1835, 28. 



U. arcaeformis, Lea, 1832, iv. 116, 17, 44. Synopsis, 13. 

 Chenu, Conchyl. Unio, pi. 12, fig. 3. 



