546 Mn Lea oti the Naiades. 



U. danaciformis. — Lea. Tr. A. P. S. 2. P. 4. fig. 3, is U. trun- 

 cata of Rafinesque, Monog. p. 31 ; the following abstracts of the 

 respective descriptions, will convince every one of this, without 

 comparing the shells. U. tnmcata. Raf. 1820. " Shell slightly- 

 thick, apices prominent, the posterior face truncated, epidermis 

 ohve. Nacre bluish white. " U. donaciformis. Lea, 1827." Shell 

 7iot very thick, beaks slightly elevated, angulated by an oblique 

 carina passing to the beaks to the posterior margin. Epidermis 

 olive — nacre pearly white." It will be remembered that these 

 claims of Mr. Lea, to these species, were asserted at a time when 

 Mr. Rafinesque's Monograph, which was published in 1820, at 

 Bruxelles, was lost sight of, and that it was only revived by a 

 translation, in 1832. 



U. securis. — Lea. Tr. A. P. S. 3. P. 11. fig. 17, is U. depressa 

 of Rafinesque, Monog. p. 34. 



U. pustulosus. — Lea. Tr. A. P. S. 4. P. 7. fig. 7, is U. hullata 

 of Rafinesque, Monog. p. 43. 



U. pustulatus. — Lea. Tr. A. P. S. 4, P. 7. fig. 9, is U. nodulata 

 of Rafinesque, Monog. p. 42. 



U. soleniformis. — Lea. Tr. A. 

 monodonta of Say, Am. G)nch. No. 



U. perplexus. — Lea. Tr. A. P. 

 hosa. Rafin. Monog. p. 56. 



U. pileus.—Le?L. Tr. A. P. S. 4. P. 18. fig. 47, is V.fexuosus 

 of Rafinesque, Monog. p. 41. 



U. sulcatus.— Lea. Tr. A. P. S. 3. P. 8. fig. 12, is U. obli- 

 quata of Rafin. Monog. p. 46. 



U. pyranidatus.—Lea. Sup. to Tr. A. P. S. 4, P. 16. fig. 39, 

 is U. rubra of Rafin. Monog. p. 55. 



U. lacrymosus. — Lea. Tr. A. P. S. 2. P. 6. fig. 8, has been 

 by some thought the U. metanevra of Rafin. Monog. p. 39. Lea 

 has mistaken the metanevra of Raf. for his U. quadrula. Monog. 

 p. 42. 



U. asperrimus.—l.ea. Tr. A. P. S. 4. P. 5. fig. 3, is the U. 

 rugosus of Barnes, in Sil. Jour. vol. vi. Jan. 1823. 



U. brevidens. — Lea. Tr. A. P. S. 4. P. 6, is evidently an acci- 

 dental variety of the U. depressa of Rafinesque. 



U. varicosus. — Lea. In the same paper is a variety of the U. 

 esopus of Green in Conts. to Mac. Lye. July, 1827. Professor 

 Green's paper is very judicious and instructive. This is the only 



