1853.] 258 
Unio nervosus, Raf. Ann. v.30. Poulson’s Trans. 22. 
Say, Amer. Conch. Synonym. of Unio, No. 6. 
U. zigzag, Lea, iil. 440, 12,19. Synopsis, 24. 
U. Donaciformis, ui. 267, 4, 3. Synopsis, 24. 
nigellus, Lea, x. 283, 24,42. Synopsis, 30. 
niger, Raf. Ann. v. 25. (Elliptio,) Poulson’s Trans. 15. 
Con. Monog. 49, 26. 
Fer. Guerin’s Mag. 1835, 27. 
Lister’s Conch. pl. 150, fig. 5. 
U. incrassatus, Lea, 1842, viii. 217, 16, 34. Synopsis, 24. 
Chenu, Conchyl. Unio, pl. 31, fig. 5. 
U. gibber, (?) Lea. 
nigerrimus, Lea, 1852, x. 268, 18, 23. Synopsis, 31. 
nigrinus, Lea, x. 284,24, 44, Synopsis, 39. 
nitens, Lea, viii. 205, 12,19. Synopsis, 29. 
Chenu, Conchyl. Unio, pl. 28, fig. 5. 
nodiferus, Con., (¢) Journ. Acad. Nat. Sc. second ser. 1. 277, 38, 4, 8. 
U. prasinus, Lea, (not Con.) Synopsis, 22. 
nodulatus, Raf. Ann. v. 41,81, 17, 18. Poulson’s Trans. 42. 
Say, Amer. Conch. Synonym. of Unio, No. 6. 
Fer., Guerin’s Mag. 1835, 28. 
U. pustulatus, Lea, 1832, iv. 79,7, 9. Synopsis, 22. 
Chenu, Conchyl. Unio, pl. 15, fig. 8. 
| ~ notatus, Lea, 1838, vi. 28, 8,22, Synopsis, 29. 
Novi-Eboraci, Lea, 1838, vi. 104, 24, 114, Synopsis, 27. 
Dekay, Zool. of New York, 194, 20, 240. 
Chenu, Conchyl. Unio, pl. 19, fig. 5. 
nucleopsis, Cox., Journ. Acad. Nat. Sc. 2d ser. i. 276, 37, 8. 
a Lea, Synopsis, 35. 
oe nexus, Say, Transylvania Journ. 1831, iv. 527. Amer. Conch. 51. 
_¢ Con. Monog. 68, 38, 1. 
Ferussac, Guerin’s p} Mag. 28. 
to U. areeformis, Lea, 1832, ‘iv. 116, 17,44, Synopsis, 23. 
notatus, Lea, 1838, vi. 28, 8, 22, Synopsis, 29. 
Chenu, Conchyl. Unio, pl. 21, fig. 3. 
| U. simus, Lea, vi. 26, 8,20. 
| Chenu, Conchyl. Unio, pl. 21, fig. 4. 
obliquus, Lam. An. sans Vert. vi. 72. 
Con. Monog. 77, 43, 2. . 
U. obliquus, Fer. Guerin’s Mag. 1835. 
U. ebenus, Lea, 1832, iv. 84,9, 14. Synopsis, 35 
Chenu, Conchyl. Unio, pl. 15, fig. 7. 
U. undatus, Desh. (not Barnes) Desh. ed. of Lam. vi. 534. 
U. mytiloides, (?) Swain. (not Raf.) 43, Malac. 270, fig. 53. 
obliquatus, Raf. (obliquaria) Ann. v. Poulson’s Trans. 46. 
Say, Amer. Conch. Synonym of Unio, No. 33. 
U. ridibundus, Say, Disseminator. 
~ U. sulcatus, Lea, 11.430, 8,12, Synopsis, 26. 
Chenu, Conchyl. Unio, pl. 13, fig. 3. 
obovalis, Raf. v.45, Poulson’s Trans. 49. 
U. solidus, Lea, vi. 13,5, 13, Synopsis, 25. 
Chenu, Conchyl. Unio, pl. 25, fig. 2. 
*obtusus, Lea, villi. 201, 11,13, Synopsis, 39. 
Chenu, Conchyl. Unio, pl. 31, fig. 2. 
occidentalis, Con. Monog. 64, 36, 1. 
Lea, Synopsis, 33. 
