THE NAUTILUS. 



VOL. XVII. APRIL, 19O4. No. 12. 



NEW SPECIES OF SOMATOGYRUS. 



I5Y UUYANT WALKER. 



Through the kindness of Mr. A. A. Hinkley, of Du Bois, 111., I 

 have had the opportunity of examining the Amnicolidce collected on 

 his recent trip to the Coosa river, and the larger portion of the 

 species herein described are from his collection. The others have 

 been received from the different sources stated in the descriptions. 



The new species collected by Mr. Hinkley are remarkable for the 

 diversity of form exhibited, which was quite unexpected in view of 

 the very general similarity in that particular of the species already 

 discovered. The collection also shows that the earlier collectors on 

 the Coosa practically ignored the smaller forms in the more exciting 

 pursuit of the peculiar Pleuroceridae of the river, and that there yet 

 remains much to be done before the molluscan riches of that wonder- 

 ful stream will be exhausted. 



The late Dr. Jas. Lewis in his " Fresh Water and Land Shells " 

 (1876), lists four species of Somatogyrus as occurring in Alabama, 

 viz : 



S. aureus Tryon. S. parvulus Tryon. 



S. currlerianus Lea. S. subglobosus Say. 



Having Dr. Lewis' collection in my possession, I am able to check 

 up his determinations in the light of our present information. It is 

 evident, from the condition of his specimens, many of which are not 

 even washed, to say nothing of having the black and ferruginous de- 

 posits removed, with which they are frequently covered, that Dr. 



