Ortmann: Families and Genera of Najades. 



267 



There were only three gravid females among them, which were' found 

 on June 22, i<)oi). 



Anatonrj normal: margin of the mantle, siphons, gill-structure, and 

 marsupium typically Unionine. In a few eases the rather short 



sa 



~,an 



\br 



Fig. 10. Elliplio crassidens (Lamarck). Male, from Allegheny River, Kelly, 

 Armstrong Co., Pa. (Cam. Mus., No. 61, 3,777.) Coll. July 3, 1908. 



mp 



Fig. 10a. Left gills of a sterile female, from same locality. (Cam. Mus., No. 61, 

 3,055.) Coll. Sept. 5, 1907. 



mantle-connection between the anal and supra-anal was found to be 

 absent. Anal with small, but quite distinct, papillae. Palpi with the 

 posterior margins connected for a short distance. 



