THE NAUTILUS. 77 



tucky and small adjacent rivers be proved before any approxi- 

 mation of the two species be accepted. 



3. The tappanianus of Lea, until recently, has always been 

 considered to be restricted to the Atlantic drainage. But Dr. 

 Ortmann, (Pr. Am. Phil. Soc, LII, 1913, p. 371), has very 

 lately discovered it in abundance in the Greenbrier and New 

 rivers in the upper Kanawha system. Its occurrence in the 

 Ohio drainage system is, therefore, established. 



As the habits of compressa and tappanianus are alike, both 

 being creek species, in view of what we now know, it would 

 seem quite as probable that tappanianus might be found in the 

 Kentucky as compressa. At any rate, it would suggest the 

 desirability of getting the facts as to what the fauna of the Ken- 

 tucky is, before jumping at conclusions. 



4. So far as I know the single valve in the Poulson collection, 

 said to be from the Kentucky and identified by Rafinesque as 

 his viridis, is not now in existence. If it is, the question as to 

 which of the later described species it belongs, can be easily 

 settled by an inspection of the shell. Conrad, who saw the 

 specimen, said that it was identical with the Juniata shell 

 described by himself as subviridis and by Lea as tappanianus. 

 Say, who also saw the shell, said that it was an entirely differ- 

 ent species. In the light of the then existing knowledge of the 

 distribution of tappanianus, and, indeed, of our own until 1913, 

 Dr. Lea was quite justified in his remark " that there is an error 

 in the habitat or the name". Mr. Frierson, who has not seen 

 the specimen, assumes that the habitat was right, but that 

 Conrad Avas wrong in identifying it with the Juniata species. 

 It would be quite as reasonable either to assume that Conrad 

 was right and the locality wrong or that both Conrad and the 

 locality were right. At any rate, in the absence of the specimen 

 itself, great caution should be exercised in making any assump- 

 tions about it. 



5. If Rafinesque had stated that his viridis came from the 

 Atlantic drainage, there is scarcely any one, who would attempt 

 to make any identification based on his description alone, who 

 would not say that it was quite surely the tappanianus of Lea. 



If the question of locality could be eliminated, I feel assured, 



