THE FAMILY NAIADES. n 



TRIANGULAR. 



inflatus. Lea. 



Symp. inflata. Lea^ in Trans. Am. P. S. 



alatus. Say. 



Unioalatus. Say. Lam. Swain. Bar. Hild. 



Mya alata. Wood. 



Symp. alata. Lea, Trans. Am. P. S. 



syrmatophorus. Lea. 



Mya syrmatophora. Gronovius. Gmel. 



Wood. Dill. 

 Hyria avicularis. Lam. Crouch. 

 Hyria syrmatophora. Sow. 

 Hyria elongata? Swain. 

 Unio caudatus.* Wagner. 

 Prisodon obliquus. Schum. 

 Prisodon truncatus. Schum. 

 Diptodon fuscatum.* Spix. 



laevissimus. Lea. 



Symp.lsevissima. Zea,inTr. A.P.S. Eaton. 

 Unio laevissima. Deshayes. 



gracilis. Barnes. Hild. 



Unio planus. Barnes. 

 Unio fragilis. Swain. 

 Symp. gracilis. Lea, in Tr. Km. P. S. Eaton. 



compressus. Lea. 



Symp. compressa. Lea, in Trans. Am. P. S. 



* On the authority of Fcrussac. 



