Qua rterly Joitnial of ConcJwlogy. 207 



REVIEW OF THE GENUS TULOTOMA, WITH 



REMARKS ON THE GEOGRAPHICAL DISTRIBUTION 



OF THE NORTH AMERICAN VIVIPARIByE. 



By A. G. Wetherby, 



Assistant Professor of Natural History in The Cincinnati University. 



In the old Lamarkian genns Faludina, several groups of fresh- 

 water mollusca were placed, which have since been separated. 

 Although these groups agree in being ovo-viviparous, and have 

 some anatomical characteristics in common, the separation of the 

 shells included by Lamark under Paluditia, into the genera Vivi- 

 para, Melaiitho, Lioplax, and Ttilotonia, is now very generally re- 

 cognized among American Naturalists, and has very greatly aided 

 in the classification of the abundant reprf'sentatives of the Vivipa- 

 ridce to be found in the various parts of the United States. 



The special object of the writer is, as briefly as possible, to 

 review the genus Tiilotonia, as hitherto understood, and to add 

 some facts, recently established, to our knowledge of the shells. 

 These facts rest upon a protracted study and comparison of many 

 hundred <;pecimens, from the largest adults to those just removed 

 from the ovaries; and taken at different localities on the Coosa, 

 and Alabama rivers, the localities being many miles apart, and in 

 different geological formations. As the specimens were obtained 

 by a collector, I have not had the very great advantage of studying 

 the Hving animals in their native habitat; a pleasure that I hope 

 the coming summer may afford. But I offer the following review, 

 in the belief that it will be found in the main correct, and with 

 the hope that others interested in these mollusks may perfect the 

 work here begun. 



The first species published, of the genus under consideration, 

 Avas the T. viagnifica, Conrad, or T. bimonilijera, Lea. Mr. Con- 



