54 THE WASATCH AND RRIDGER FAUX^^. 



free, ovate posterior outline, and its superior surface is covered with a thick 

 layer of dense bone, which has not the brilliant surface of ganoine. This 

 substance is thrown into elevated, coiTugated ridges, which are generally 

 transverse to the long axis of the bone, and inosculate and are interrupted 

 frequently. The spaces between are as wide as the bases of the ridges. 



Measurements. 



u. 



Width of bone 042 



Thickness of bone 012 



Found in the Bridger bad lands of Ham's Fork, Wyoming. 



Clastes atrox Leidy. 



Cope, Annual Report U. S. Geol. Surv. Terrs., 634, 1872 (1873). 



Lepidosteus atrox Leidy, Proc. Acad. Nat. Sci. Phila., 1873,97. — Report U. S. Geol. Snrv. Terw., i, 1873, p. 

 189, PI. x.\xii, tigs. 14-15. 



Abundant, and represented by both rough and smooth scales, the 

 former from the anterior part of the body. As this species has been already 

 described by Leidy, I only refer to my Plate II, figs. 1-24. 



Clastes cyclifeeus Cope. 



Annual Report; U. S. Geol. Surv. Terra., 1872 (1873), p. 634. 

 Plate II, figs. 25-45. 



Established on numerous remains of a small species, in which the scales 



are rather wide, and generally with obtuse extremital angles, and frequently 



in certain regions of the body entirely rounded at the posterior border. 



Fragments of the cranial bones are ornamented with scattered tubercles of 



ganoine of rounded form, and not distributed in lines as in some species. 



In a fragment from the posterior part of the mandible, there is a single row 



of large teeth, with a series of minute ones between them on the outer 



edge of the bone. The external face presents a smooth, superior surface, 



and a rugose inferior portion which is marked by irregular lines of points 



of ganoine. 



Measuremeiits, 



M. 



Depth of dentary bone WCO 



Width of above 00,\5 



L<'iiKt)i of a Hcalc (exposed face) OOGO 



Width of a scale (exposed face) OOtX) 



From the Mammoth Buttes, Washakie Basin. 



