1853.] 257 



Unio rivularis, Con. Journ. Acad. Nat. Sc. 1853, iii. 2d series. 

 U. declivis, Con. (not Say) Monog. 45, 23, 1. 

 Kttst. Chemn. Unio, pi. 14, fig. 1. 

 Lea, Synopsis, 33. 



Roanokensis, Lea, 1838, vi. 27, 8, 21, Synopsis, 32. 



rosaceus, Behay, Zool. of New York, 192, 39, 355, 356, and pl.40, fig.357. 



rotundatus, Lam. An..sans Vert. Desh. ed. vi. 538. 

 U. snborbiculata, Xaw. Desh. ib. 546. 



decorticata, Raf. Ann. v. 36, Poulson's Trans. 33. 

 glebulus, Say, Amer. Conch, pi. 34. 

 subglobosus. Lea, v. 30, 2, 3. 

 rotundatus. Lea, Synopsis, 34. 



rubellus, Co7i. New Fresh Water Shells, 38, 6, 2. 

 Lea, Synopsis, 34. 



Ruber, Raf. v. 48, Poulson's Trans. 55. 



U. pyramidatus, Lea, iv. 109, 16, 39, Synopsis, 25. 



Chen7i,Conc\iy\. Unio, pi. 16, fig. 5. 



U. coccineus. Jay, (not Hildreth,) Catalogue, 66. 



rndis, Co7i. Monog. 76, 43, 1. 

 U. Ravenelianus, Lea, v. 32, 3, 5, Synopsis, 26. 



rufusculus, Lea, 1852, x. 258, 14, 7, Synopsis, 33. 



Rumphianus, Lea, 1852, x. 276, 22, 34. 



sagittiformis, ieo;, 1852, x. 277, 22,35, Synopsis, 37. 



Sapotalensis, Lea., viii. 233, 21, 47, Synopsis, 29. 



CAe/m, Conchyl. Unio, pi. 33, fig. 4. 

 saxeus. Con. Monograpby of North American Unionidae, 109, 60, 1. , 



satur. Lea, 1852, x. 265, 17, 19, Synopsis, 24. 



Lea, Synopsis, 27. 



seeuriformis, Con. Journ. A. N. S. i. 275, 37, 1. 



semigranosus, V. d. Btisch. 



Phillippi, Conchyl. Unio, 1, 1, 1, 2, 3. 

 Lea, Synopsis, 20. 



Shepardianus, Lea, 1834, v. 95, 13, 38, Synopsis, 35.. 

 Con. Monog. 70, 39. 



simns, Lea, 1838, vi. 26, 8, 20, Synopsis, 31. 

 sintoxia,* Raf. v. 44, Poulson's Trans, v. 48. 

 sordidus. Lea, 1852, x. 254, 12, 1. Synopsis, 33. 

 Sowerbianus, Lea, 1834, v. 68, 10, 28, Synopsis, 25. 



Con. Monog. 66, 37, 1. 

 sparsus, Lea, 1841, viii. 242, 25,58, Synopsis, 22. 



Chenu, Conchyl. Unio, pi. 26, fig. 2. 



spatulatus, Lea, 1845, x. 80, 8, 22. 



spinosus. Lea, vi. 57, 16, 50, Synopsis, 23. 

 Chenu, Conchyl. Unio, pi. 22, fig. 6. 



splendidus. Lea, vi. 70, 19, 61, Synopsis, 27. 



Cheyiu, Conchyl. Unio, pi. 17, fig. 7. 

 stagnalis. Con. Journ. Acad. Nat. Sc. 2d ser. i. 275, 37, 2. 



Lea, Synopsis, 27. 



* The specimen in Mr. Poulson's cabinet labelled sintoxia by Rafinesque is 

 a large compressed shell, similar in outline to U. coceineus. Length 3| inches j 

 height 3 inches. 



