634 GEOLOGICAL SURVEY OF THE TERRITORIES. 



with a thick layer of dense bone, which has not the brilliant surface 

 of ganoiue. This substance is thrown into elevated corrugated ridges, 

 which are generally transverse to the long axis of the bone, and inoscu- 

 late and are interrupted frequently. The spaces between are as wide as 

 the bases of the ridges. 



Measureinents. 



M. 



WiGlthof bone 042 



rJiickness of bone 012 



Found in the Bad Lands of Ham's Fork. 



Clastes atrox, Leidy. 



Lepidosteus-atrox, Leidy. Proceed. Acad. Nat. Sci., Philada., 1873. 



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

 former from the anterior part of the, body. 



Clastes cycliferus, Cope. 



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 pos- 

 terior 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. 



Measurements. 



M. 



Depth of dentary bone.. 00' 



Width of dentary above 0055 



Length of a scale, (exi>osed face) 0060 



Width of a scale, (exijosed face) 0060 



Thickness of cranial bone 



From Mammoth Buttes. 



Clastes glaber, Marsh. 



Lepidosteus glahei', Marsh. Proceed. Acad. Nat. Sci., 187. 



Abundant. 



PAPPICHTHYS, Cope. ' I 



Gen. nov. Halecomorphorum. 



Family Amiidae : YertebrsB short, the dorsal with prominent dia- 

 pophysis ; the sides of the centrum striate- grooved. Maxillary bone with 

 a supplementary bone on its distal upper border, and supporting a single 

 series of teeth. Dentary bone with but one series of teeth j surface of 

 cranial bones sculptured. 



This genus differs from the existing Amia, in the presence of only one 

 series of teeth, instead of several, on the bones about the mouth. The 

 posterior part of the dentary bone, or perhaps another element, is cov- 

 ered with fine graniform teeth, as in Amia calva. 



Species of the genus are numerously represented in the beds of the 

 Bridger Eocene. Some of them have been referred to Ainia by Marsh. 



