14 



SYNOPSIS OF 



m 

 pq 

 Z 

 O 



S 



H 

 O 



o 



QUADRATE. 



*Nicklinianus.t I-ea. 

 *coelalus. Con. 



*muUiplicatus4 Lea. 



Unio heros. Say, in Disseminator. 

 Unio undulatus. Say, Am. Couch. 



No. 2. Deshayes. 

 Unio heros. >S'ai/, Am. Conch. No. 6. 



*undi)latus. Bar. Fakn. Hild. Desk 

 Unio costatal Raf. 

 Unio costalus. Con. 



*plicatus. Lesueur. Say. Bar. Eat. Hild. 

 Unio Peruviana. Lam. 

 Unio rariplicata. Lam. 

 Unio Dombeyanus. Valen. 

 Unio undulata. X)e«A. 

 Unio multipHcata. Desk. 



*trapezoides. Lea. 



Unio crassidens. Lam. Var. a. 

 Unio interriiptus.§ Say. 



TRIANGULAR. 



*ambiguus. Lea. 



Caslalia ambigua. Lam. D'Orh. 

 Unio ambigua. Blain. Desk. Sow. 

 Mya ambigua. Wood. 

 Tetraplodon pectinatum. Spix. 



^ i 

 w .1 



TRIANGULAR. 



Cast, quadrilalera.y D'Orb. 

 Cast, inflata. D'Orb. 



*foliatu9.t Hild. 



Unioflexuosa? Raf. 

 Unio flexuosus. Con., in text, Mono- 

 graph, page 8. 

 Unio fohatus. Con., in plate 4, Mo- 

 nograph. 



OVAL. 



*pUciferus. Lea. 



WIDE. 



*multistriatus. Lea. D'Orb. 

 Diplodon ellipticum'? Spix. 



*subtentus. Say. Con. 



*Conradicus. Lea. 



*acutissimus. Lea. 



*Murchisonianus. Lea. 

 Unio DouglasiiE. Gray. 



*Grayanus. Lea. 



ARCUATE. 



ponderosus. 



Lea. 



Mya ponderosa. Solan. Dill. 

 Mya crassa. Wood. 



t This distinct and beautiful species was described from a single valve not entirely perfect. When the 

 whole shall be found perfect, I think it likely to prove symphynote. 



X When I described the multiplicatus in 1830, I had had several specimens for two or three years, and was 

 not aware that Mr Say had published a shell under the name of heros, which he subsequently abandoned as the 

 undulatus of Barnes ; but in 1834 reclaimed as heros. I consider that Mr Say's abandonment of the species 

 entitles me to it, if my previous claim be not sufficient. 



§ Mr Say, in his " Synonymy," claims precedence in this species, althougii my Memoir bears date May 

 1830, while his is December 1831. (See Transylvania Journal, Vol. V.) The reader will not after this he 

 surprised to be told that Mr Say does not allow me, in his very incorrect " Synonymy," to be the discoverer of 

 a single new species of Unio from our western waters ! ! I may be allowed also to state, that I do not under- 

 stand why he gives the same name to two of his different numbers : "thus, he calls No. 17, U. interruptus, Ra- 

 fin. ; and No. 47, U. interruptus, Say. The species are evidently distinct. 



II I owe to the kindness of M. D'Orbigny specimens of this and inflata. I regret, however, that I am compelled 

 to differ in opinion with this distinguished naturalist, beheving, as I do, that there has been as yet observed but 

 one species of Lamarck's Castalia. 



t The male of foliatus is certainly a triangular shell— the female differs in form very much, having a deep 



