G2 



UNIO. 



a: 



I 



OBOVATE. 



*Sikkimensis. Lea. 



*papyraceus. Gould. 



*Boydianus. Lea. DeJcay. Chenu. 



Floridensis. Lea. 



pellucidus. Lea. 

 *amygdalum. Lea. 

 *Saladoensis. Lea. 

 *lenior. Lea. Chenu. 

 *hyalinus. Lea. 

 *nigrinus. Lea. 



*Tappanianus. 1 Lea. Han. 

 Unio viridis. Con. 



*pertenuis. Lea. 

 *foliaceus. 2 Gould. Blan. 

 *obtusus. Lea. Chenu. 



ARCUATE. 



*crassus. s Eetz. Speng. Nilss. Schrenlc. 

 Unio crassissimus. Fer. Des Moul. 



Grat. Jferm. Han. 

 Unio auricularius. Speng. 

 Unio margaritacea. Drap. 



( ARCUATE. 



Unio sinuata. Retz. Lam. Children* 



Blain. Dup. Desh. MenJce. Rossm. 



Graells. Puton. Reynies. Gassies. 



Grat. Moq. 

 Unio rugosa. Pair. 

 Unio araris. Barbie. 

 Unio Barraudii. Bonhome. Grat. 

 Potamida sinuata. Swain. 



*decumbens. Lea. 



*monodontus. J Say. Sh. & Eat. Desh. 



Han. 

 Unio soleniformis. Lea. Chenu. 



*Lazarus. Lea. 

 *arctatus. Con. Han. 

 *emarginatus. Lea. Chenu. Han. 

 *Laonensis. Lea. 



Being unacquainted with the following species, 

 I have deemed it best simply to insert a list of 

 them, with the hope of their being determined at 

 a future period: 



Unio Abyssinicus. Mart. 

 Unio acuminatus. H. Adams. 

 Unio seruginosus. Morelet. 

 Unio Aleroni. Mass. 

 Unio altus. Con. 

 Unio antiquatus. Anton. 



I A fine suite of this species has been kindly sent to me recently by Prof. Haldeman, of Columbia, 

 Penn., taken from the Susquehanna River at that place. In most of them, I find the cardinal teeth of 

 the left valve to be trifid, and the lateral teeth of the same valve somewhat divided. In the right valve, 

 the cardinal tooth is nearly as long as the lateral tooth ; in this taking somewhat of the character of 

 Triquetra subviridis, Klein. (Hyria of Lamarck). 



I 1 am disposed to think that this may prove to be the same with Javanus (nobis). 

 8 See note to Margaritana margaritifera. 



* I think Mr. Children meant this species, but his figure (69) is evidently Unio alatus, Say, although 

 he cites it as European. 



6 This properly belongs to Margaritana. It is closely allied to M. margaritifera. See my notes on 

 the soft parts, Observations, vol. x. p. 58, and vol. vii. p. 43. 



