68 Trans. Acad. Sci. of St. Louis. 



may be made. The present list contains 61 species and 

 12 varieties of land shells, and 46 species and 4 varieties 

 of water shells. 



Acknowledgments are due to Messrs. Bryant Walker, 

 A. C. Billups, V. Sterki, F. C. Baker and B. Shimek for 

 the identification of shells submitted to them. 



Binney in his Manual of American Land Shells divides 

 the United States into three provinces — the Pacific, Cen- 

 tral and Eastern. The latter includes all of North 

 America north of Mexico and east of the Eocky Moun- 

 tains. It is divided into three regions, the Northern, 

 Interior and Southern; Missouri is in the Interior Re- 

 gion. The Ozarkian fauna belongs to it, and is found 

 in the Ozark Mountain regions of Missouri and south 

 and west. This fauna contains some species which are 

 peculiar to it, and others which have been derived from 

 the Cumberland subregion, although the low lands be- 

 tween do not contain them; other species have come 

 from the Texas subregion. That part of the Ozark re- 

 gion which is in Missouri does not have any species that 

 is peculiar to that part of it. The State north of the 

 Ozark region has, of course, many species that are 

 found widely scattered in the Interior Region. 



There have not been many new species and varieties 

 described from Missouri. The following is the list : 



Bulinus distortus Hald, St. Louis. 

 Bythinella aldrichi Call, Reynolds county. 

 Goniobasis potosiensis Lea, Potosi. 

 Goniobasis ozarkensis Call, Shannon county. 

 Lymnaea columella var. a Say, Cold Water creek. 

 Physa crandalli Baker, Pettis county. 

 Planorbis sampsoni Ancey, Pettis county. 



The following list of species gives the counties in 

 which the author has collected each, and shows in paren- 

 thesis the number of specimens from each locality in the 

 collection of the author, it being in many cases the total 

 number found. Reference is also made to reports of 



