2C2 ROY L. MOODIE. 



there are set fine serrated tooth-like projections varying in num- 

 ber from fifteen to sixty. 



Cope announced the discovery of similar bodies in the Linton, 

 Ohio, beds in 1 885 x and compared them to the elements described 

 and figured by Fritsch as " Kammplatten." He says in regard 

 to them : " They consist of a curved rod terminating in a secund 

 expansion, whose projecting edge is divided into fine teeth like a 

 comb " and they " differ from those described by Fritsch, in the 

 greater curvature of the shaft in the direction to which the teeth 

 present. Its axis is nearly at right angles to that of the body of 

 the bone." In this connection he refers to similar bodies found 

 by him in the Laramie deposits of Montana to which he had given 

 the name Ceratodus hieroglyphus which he later changed to Arotas 

 hievoglypJius. Hay in his " Catalogue of Fossil Vertebrata of 

 North America" retains the name under Ceratodus. 



Cope's description of the element in question is as follows : 

 " The dentigerous plate is thin and dense, and has the appearance 

 of a short toothed comb with a handle. The tooth-like points 



Fig. .3. Cope's Ceratodus hieroglyphus from the Laramie of Montana. X 4- 



are the extremities of low ridges, which are arranged nearly at 

 right angles to a wide longitudinal elevated half of the osseous 

 base. They are separated by shallow grooves from each other 

 and are not continuous with the basis just mentioned, which rises 

 abruptly above them. They are smooth. The ' handle ' above 

 alluded to is triangular in section having two bevels on the side 

 supporting the tooth ridges. The lower face of the bone is smooth. 



Measurements. m. 



Total length 013 



Length of dentigerous portion 010 



Total width 0045 



Width of dentigerous portion 0020 



" There are thirteen teeth in the length " 2 (Fig. 3). 



x Cope, 1885, Pal. Bull., No. 40, p. 405. 



2 Cope, 1876, Proc. Acad. A T at. Sci. Phila., p. 260. 



