PERMIAN VERTEBRATES 699 



described by Cope are now missing from the collection, and so 

 cannot be figured. 



Several specimens are preserved in the collection which were 

 never described by Cope. I have refrained from giving new 

 names to these, as it is altogether probable that the seemingly 

 new forms are but portions of the skeleton of animals that have 

 been named from other parts of the skeleton. The numbers 

 given at the close of each description, are the record numbers 

 of the Paleontological collection in Walker Museum, at the 

 University of Chicago. 



Janassa strigilina Cope. Plate I, Figs, la, \b, \c. 



Strigilina linguceformis Cope, 1877, Proc. Am. Phil. Soc, 



p. 53. (Specific name preoccupied in 1868 by Atthey.) 

 Janassa strigilina Cope, 1881, Am. Nat., p. 163. 

 Janassa strigilina Woodward, 1889, Cat. Foss. Fishes Brit. 



Mus., Pt. I, p. 38. 



Generic characters : "The tooth is a flat, osseous plate, whose outline is 

 pyriform, the wider end recurved in one direction as the transverse cutting 

 edge ; the other extremity narrowed and recurved in the opposite direction 

 as the root. The side from which the cutting edge arises is crossed by 

 numerous plicse from the base of the root to near the base of the cutting 

 edge; the opposite side is smooth." 



Specific characters : "The plicate surface terminates behind in a median 

 angle, at the base of the root. There are eight plicae which all cross the 

 plane, excepting the sixth, which is interrupted in the middle by the strong 

 angulation of the seventh, which touches the fifth. The lateral extremities 

 of the right are in contact with the base of the recurved cutting portion. 

 The latter is convex transversely, leaving a smooth surface between it and 

 the eighth plica. The smooth side of the tooth is shining, and there is a 

 shallow fold, which passes around its side and crosses just at the base of the 

 recurved cutting lamina." 



MEASUREMENTS. 



" Total length of the plane ----- .008 m 



Width at base of the cutting lamina - - .006 



Width at the base of the root .._■■-- .004 



Thickness of plane portion -..--- .0015 



[No. 6500.] 



