316 KANSAS UNIVKKSITY SCIENCE BULLETIN. 



Interior: Pseudocardinals fairly large, erect, pointed, rag- 

 ged, double in the left and single in the right valve Laterals 

 short, low, heavy, straight, very oblique ; interdentum long, 

 broad, and smooth. Anterior adductor cicatrix rather small, 

 located in front of the pseudocardinals, much longer than 

 wide, well excavated. Posterior cicatrices small, well im- 

 pressed, distinct. Dorsal cicatrices forming a line on the 

 under surface of the interdentum. Pallial line impressed 

 only anteriorly. Hardly any beak cavity ; cavity of the shell 

 small. Nacre a beautiful white, slightly iridescent posteriorly. 



I'm. ra. 



0.36 (Coll. K. S. A. C.) 

 .21 



|g j (Coll. Kan. Acd. ScL) 



'.31 I 



C. alberti is limited in range to southern Kansas, Missouri, 

 Indian Territory, and Arkansas. Its distribution in Kansas 

 is limited to the clear-water streams of the southern drain- 

 age. The streams in which it has been found are Fall river 

 (Mead, Popenoe), Verdigris river (Cragin, Popenoe) , and 

 Neosho river (Fenis). Even in these streams it is a rare 

 species. 



As compared with specimens before me from the White 

 river, Arkansas, the Kansas form is a much larger, more 

 inflated and massive shell, with smaller muscle cicatrices. 

 Doctor Call described specimens from the Neosho and Verdi- 

 gris rivers as a new species [Vnio popenoi) , but later on 

 worked out the synonmnv and placed it under U. alberti 

 (5-6) . 



There is no other Unio in Kansas which can be confused 

 with this one. The peculiar markings of the epidermis and 

 the extreme flattening of the beaks for about one-third the 

 distance vertically across the disk is very characteristic. 



Genus OBLIQUARIA < Rafinesque, 1820) Simpson. 



"Shfll inflated, solid, oval, ending in tolerably sharp point 

 behind, having a row of large compressed longitudinal knobs 

 running off from the beaks to the center of the base, those 

 on one valve alternating in position with the knobs of the 



