148 KANSAS UNIVERSITY SCIENCE BULLETIN. 



American affinities represented in the Whitehorse sandstone 

 show a decided decline in the Quartermaster beds, while 

 the reverse is true of the foreign element, probably due to 

 slower immigration. 



DESCRIPTION OF SPECIES. 



The drawings of the last two plates and text figures of this 

 article are by Miss Maud Siebenthal, of Bloomington, Ind. 



SPIRORBIS sp, 



Plate VI, fignre 10. 



Shell minute. Only the attached surface of the two flat 

 whorls shown on the cast of a shell. For the first half whorl 

 the shell is nearly straight. The curve of the spiral begins 

 abruptly. Greatest diameter a little less than a millimeter. 



Whitehorse spring, Oklahoma ; rare, 



SERPULA? sp. 



Plate V, figure 5. 



A very minute cast of a serpulid (?) worm on the internal 

 cast of a shell. The greatest diameter of the coil is about a 

 half millimeter. 



Dozier, Tex. ; very rare. 



STENOPORA sp. 



A species, probably of this genus, was found at Whitehorse 

 spring and at Dozier. Prof. A. F. Rogers writes me that it 

 is practically impossible to identify them, stating: "I would 

 call the one from Dozier Stenopora sp., and the one from 

 Whitehorse the same." There was also an encrusting form 

 from Whitehorse. 



DIELASMA SCHUCHERTI Beede. 



Plate V, figures 1-lm. 



Dielasma schucherti Beede. Inv. Pal. Red Beds, p. 7, plate I, figs. 1-lc, 

 1902. 



Shell rather small, biconvex, biplicate, subelliptical in out- 

 line, slightly tapering at the beak. The cast shows an arcu- 

 ate pedicle valve, nearly equally convex except in front where 

 it becomes somewhat flattened and contains two depressions, 

 corresponding to the two folds in the other valve. The first 



