;*20 ORTMANN— THE ALLEGHENIAN DIVIDE. [April 1 8, 



Unio lanceolatus Lea, probably =3. Elliptic) productus (Conr.) 



4. Symphynota tappaniana (Lea) 



Unio collinus Conr. =5- Alasmidonta collina (Conr.) 



Alasmodon undulata Say =6. Alasmidonta undulata (Say) 



7. Strophitus edentulus (Say) 



Unio constrictus Conr. =8. Eurynia constricta (Conr.) 



Alasmodon marginata Say 



Anodon Cataracta Say 



Anodon marginata? Say 



I did not find U. lanceolatus, but in its place Ell. productus is 

 very abundant, so that, I believe, Conrad confused these two species. 

 Anodonta marginata is given by him as doubtful, and we may rest 

 assured that this (northern) species is not found here. But it is 

 quite possible that Alasmodon marginata (now Alasmidonta vari- 

 cosa) and Anodonta Cataracta are here, and I do not hesitate to add 

 these to my list. My list has two species, not mentioned by Conrad. 

 Thus we would have ten species in the upper James drainage. The 

 five species common to the headwaters of the more northern Atlantic 

 streams are again here, there is one species {Symphynota tappan- 

 iana) known from upper Susquehanna and Potomac, one species 

 {Ell. productus) , known from upper Potomac, and three species, 

 which turn up here for the first time : 



Lexingtonia subplana 

 Alasmidonta collina 

 Eurynia constricta 



These additional elements are undoubtedly more southern types, 

 which reach here their most northern station. 



VI. The Fauna of the Upper Roanoke River. 



Only the uppermost Roanoke is known to me. It drains a rela- 

 tively small portion of the Allegheny Valley, chiefly in Roanoke and 

 Montgomery Cos., Va., and has the following, poor fauna : 



