1 20 THE COAL MEASURES AMPHIBIA OF NORTH AMERICA. 



are roughnesses on the bone for the attachment of muscles. The radius and ulna 

 are subequal in size. They are both expanded more proximally than distally. The 

 carpus was cartilaginous. An additional specimen of this species is figured on plate 

 1 6, fig. 5. This adds to our knowledge of the pelvis especially. 



MEASUREMENTS OF THE TYPE. 



mm. mm. 



Length of entire specimen So Width of various portions of ulna same as radius. 



Length of tabulate horn of skull 20 Length of the only phalanx preserved 5 



Width at base 4 Length of vertebra 5 



Width at tip . . .... 2.5 Width of vertebra ; 



Length of right humerus 16 Length of longest rib 17 



Width at middle of shaft . . .... 3 Width of rib at widest part . . .... 1.5 



Width at proximal end .... 5 Width of clavicle .... 18 



Width at distal end 5.5 Length of clavicle 20 



Length of radius 9 Length of interclavicle 25 



Length of ulna ... 9 Width of interclavicle 16 



Width of radius at proximal end 2.5 Length of single side of chevron scute 7 



Width at middle 1.5 Width of same .25 



Width at distal end 2 



The specimen (No. 2566, Am. Mus. Nat. Hist.) on which Cope based his 

 Tudi (tin us mordnx is composed of two plates of the above-described species. 



Diceratosaurus laevis Moodie. 

 MIIODIE, Jour. Geol., xvn, No. i, p. 63, figs. 13, 14, 1909. 



Type: Specimen No. 102 (8680 G), American Museum of Natural History, 

 where it forms part of the Newberry collection. 



Horizon and locality: Linton, Ohio, Coal Measures. 



The species is represented by an almost complete skull, which had been identi- 

 fied previously by Cope as Tuditanus radiatus. The specimen consists of the 

 impressions of the bones of the cranial roof, the bones themselves having disap- 

 peared. It is not probable that the dorsum of the skull was smooth. The details 

 in the structure of the skull have been ascertained quite definitely. There can be 

 no doubt that the arrangement of the elements is accurate, as shown in figure 24 A. 

 The supratemporal, as in Erpetosaurus tabidatus Cope, is excluded from the parietal. 



The form of the skull at once recalls that of the species D. pinictolincatus, as 

 figured by Jaekel (see plate 15). The orbits are located in nearly the same region 

 of the skull and the sutures separating the cranial elements are quite similar in the 

 anterior portions. The species D. I avis is based on the divergent character of th e 

 horn-like protuberances which project from the squamosals. The horns of D, 

 punctolineatus are convergent. The present skull is also smaller and the parietals 

 in D. Icevis are much larger than in the type species. In the type species, also, the 

 pineal foramen is located well forward in the parietal, while in the present form the 

 foramen is located well posterior. 



The skull is almost rectangular. The nostrils are elongate ovals. The orbits 

 are circular and the distance between them is equal to two-thirds of the dimensions 

 of the orbit. They are located well forward in the skull and are bounded laterally 

 by the maxillaries. The nostrils have much the same character as in the type form, 

 being broadly oval. 



The premaxillae are elongate transversely, being about twice as long as wide. 

 They are identical in shape and relations with the same elements in D. pitnctoline- 

 utns Cope. The nasal is nearly square and forms the interior boundary of the nos- 

 tril. The frontal is elongate in the median length of the skull and it is acuminate 



