92 THE NAUTILUS. 



shells from Kansas and Oklahoma. As this region is not well 

 known conchologically, it has been thought that a list of the species 

 would be of value as a contribution to the subject of geographic dis- 

 tribution. The region includes Grant ajid Kay counties, Oklahoma, 

 and Sumner, Harper and Kingman counties, Kansas. The collection 

 is now deposited in the Chicago Academy of Sciences. My thanks 

 are due to Mr. Bryant Walker and Dr. V. Sterki for assistance in 

 determining critical material. 



PELECTPODA. 



Lampsilis anodontoides (Lea). Chikaskia River, Tonkawa, 

 Oklahoma. 



Lampsilis suhrostrata (Say). Spring Creek, Grant county, 

 Oklahoma. 



Lampsilis parva (Barnes). Bluff Creek, Grant Co., Oklahoma. 



Lampsilis purpurata (Lamarck). Chikaskia River, Tonkawa, 

 Oklahoma. 



Lampsilis gracile (Barnes). Shoofly Creek, Williston, Oklahoma. 



Plagiola donaciformis (Lea). Chikaskia River, Hunnewell, 

 Kansas. 



Tritogonia tuherculata (Barnes). Chikaskia River, Tonkawa, 

 Oklahoma. 



Anodonta grandis Say. Chikaskia River, Tonkawa, Oklahoma; 

 Chikaskia River, Williston, Oklahoma. 



Anodonta corpulenta Cooper. Duck Creek, near Tonkawa, 

 Oklahoma. 



Anodonta imbecilis Say. Shoofly Creek, Williston, Oklahoma. 



Symphynota complanata (Barnes). Chikaskia River, Tonkawa, 

 Oklahoma; Chikaskia River, Williston, Oklalioma. 



Unio tetralasmus camptodpn Say. Spring Creek, Anthony, Kansas. 



Unio tetralasmus say* Ward. Spring Creek, Grant Co., Oklahoma. 



Quadrula undulata (Barnes). Chikaskia River, Tonkawa, Okla- 

 homa; Chikaskia River, Drury, Kansas; Shoofly Creek, Williston, 

 Oklahoma. 



Quadrida undulata latecostata (Lea). Shoofly Creek, Williston 

 Oklahoma. 



Quadrula lachrymosa (Lea). Chikaskia River, Tonkawa, Okla- 

 homa; Chikaskia River, Drury, Kansas. 



Quadrula pustidosa (Lea). Chikaskia River, Tonkawa, Okla- 

 homa; Chikaskia River, Drury, Kansas. 



