THE KANSAS UNIVERSITY 

 SCIENCE BULLETIN. 



Vol. VII, No. 7] JANUARY, I9l3. [;'o"°xv.fNr7 



NOTICE OF A NEW FISH FROM THE PERMIAN OF 

 KANSAS, WITH DESCRIPTION. 



BY H. T. MARTIN. 



Ctenoptychius semicircularis Newberry and Worthen. 



(Contribution from the Zoological Laboratory, No. 206.) 



A SINGLE TOOTH referable to this species was discovered 

 about a year ago by Mr. J. W. Giydden, of Lawrence, 

 while working on a block of stone shipped here from the 

 quarries situated about thirty miles east of Arkansas City, 

 Kan. The formation from which the block was secured is 

 evidently Permian. When received the tooth was firmly em- 

 bedded in a mass of limestone. By careful work the specimen 

 has been entirely cleaned from the adhering matrix, and now 

 presents a nearly perfect tooth. 



Like similar teeth described by Newberry (Geological Sur- 

 vey of Ohio, vol. 2, page 41), this specimen has a covering of 

 enamel on the upper or dentigerous portion, of a light gray 

 color ; the enamel has a clearly defined line of demarcation on 

 the outer or convex side, which extends 9 mm. down from the 

 tip of the large center denticle, while the whole inner or con- 

 cave cup of the tooth is entirely covered with enamel, which 

 overlaps the inner wall or heel of the tooth, and extends 4 mm. 

 down the outside of this inner edge. The tooth has seven saw- 

 tooth-like denticles, forming the higher semicircle and what is 

 probably the outer edge, the center denticle much the largest. 

 The enamel surface is very smooth and polished. The root or 

 base of the tooth is of a brown color, and is lightly scored all 

 around with vertical lines. A cross section of the base shows 



Received for publication September 3, 1912. 



(185) 



