28 



UNIO. 



III. SUBGENUS UNIO. 1 



K 

 E- 

 C 

 V. 



a 



TRIANGULAR. 



*Cumingii. Zea. 



JJnio Cumingii. Reeve? (No. 264.) 



gigas. Sivain. Lea. 

 Megadomus gigas. Sivain. 



*Nicklinianus. Lea. Han. 



*eximius. Lea. Mart. 



*Boykinianus. Lea. Chenu. 



*inflatus. Lea. Klist. Han. 



Symph. inflata. Lea, in Trans. Am. 



P. S. 

 Unio Alabamensis. Con. 



*delphinus. Grun. Lea. Kust. Chenu. 



*alatus. Say. Lam. Swain. Bar. ■ 



Hild. Menhe. Adams. Kust. 



Dehay. Potier. Deshayes. Con. 



Sow. Chenu. Han. 

 Mya alata. Wood. Hat. 

 Symph. alata. Lea. Sh. & Eat. 

 Lymnadia alata. Sow. Sivain. 

 Metaptera alata. Stimpson. (Agass. 



MSS.) 



*Heermannii. Lea. 



TRIANGULAR. 



*Hainesianus. Lea. Mart. 

 Unio impjericdis. More. 



subtrigonus. Sow? 



*superbus. Lea. 



Unio macropterus.* Dunk. 

 Unio velaris. Bens. 



*gravidus. Lea. Mart. 

 Unio abnormis. More. 



*delpliinulus. 5 More. 



*la3vissimus. Lea. Adams. Han. 

 Symph. Isevissima. Lea. Sh. & Eat. 



Swain. 

 Unio Isevissima. Deshayes. 



*Myersianus. Lea. 



Ortonii. Lea. 



*Housei. Lea. Mart. 



*gracilis. 6 Barnes. Hild. Desh. Han. 

 Adams. 

 Unio planus. Barnes. 

 Unio fragilis. Sivain. Kust. 

 Symph. gracilis. Lea. Sh. & Eat. 



1 Eetzius, Nova Testaceorum Genera, 1788. 



2 Judging from the figure of Reeves, I should think it had been taken from Marg. complanata, Barnes. 

 ' The figure is very much like that of Hainesianus, Lea, and inay he a half grown specimen. 



4 Dr. Dunker received it from Danu-Luar River, Sumatra. 



5 A well-characterized species from Honduras. 



6 Mr. Swahison's description of fragilis appeared in his Zool. TIL, dated 1822-1823 ; and Mr. Barnes's 

 in Silliman's Journal for April, 1823. As I do not know which really was issued first, I have preferred 

 to give preference to Mr. Barnes's name, by which the shell has been universally known among our con- 

 chologists. 



