280 KANSAS UNIVERSITY SCIENCE BULLETIN. 



distribution and synonymy. While this list will always be 

 of great value to those working on the Unios of the western 

 Mississippi region, it is preliminary in its character and 

 hardly available to the average student. Modern synonymy, 

 much of which Doctor Call has himself worked out, has re- 

 duced this list to forty species and three subspecies. 



In this catalogue are listed sixty-one species and five sub- 

 species. There is no doubt that future collecting will add 

 many more species to this list. The author has tried to 

 make certain of the identification and locality of every species 

 listed, and, with three exceptions,* has examined native 

 specimens of each. In the great majority of cases a large 

 series was available for the study of each species. 



The greater part of the material upon which this paper is 

 based was obtained from the collection of the University of 

 Kansas (built up through the efforts of Dr. F. H. Snow) and 

 from the collection of the author from Douglas, Franklin, 

 Johnson, Jefferson and Cherokee counties, and the Neosho 

 river near the state line. Several correspondents over the 

 state have contributed data and material. The author has 

 also examined the collections of the Academy of Science, at 

 Topeka ; Ottawa University, at Ottawa ; Kansas Agricultural 

 College, at Manhattan ; and Washburn College, at Topeka. 

 In the last-named institution is deposited most of the material 

 upon which Doctor Call based his report. 



The classification followed in this paper is that of Simp- 

 son's "Synopsis of the Naiades" (20), and the description of 

 the genera and higher groups are extracts from that acknowl- 

 edged authority. Simpson's synonymy has been accepted in 

 all cases save that of Anodonta bealii, which the author feels 

 convinced is only another form of the highly variable Ano- 

 donta grandis. While strongly opposed on principle to varie- 

 ties or subspecies among the Naiades, the author has adopted 

 a number for the sake of convenience. Only those synonyms 

 which seem to be of the most importance are given. Lind- 

 hall's correction of the orthography of the Naiades (24) has 

 been adopted throughout. 



As a number of measurements have been given in connec- 



* Lampailis higginsii, Quadrula speciosa, Q. aspera. 



