98 THE COAL MEASURES AMPHIBIA OF NORTH AMERICA. 



as E. radiatus (Geol. Surv. Ohio, n, pt. II, pi. 34, fig. 3), but the identification is 

 doubtful and the figure shows structures which I am unable to identify in the speci- 

 men. Nothing of importance is to be learned from the other two specimens, except 

 that they show a diversity of size. They consist of incomplete skulls, concerning 

 which Cope (123) remarks: 



"There are no mucous canals. The sculpture consists of strong ridges radiating and 

 inosculating. Radiation is more uninterrupted on both jugal, supratemporal, and anterior 

 part of the tabulare; on the first they originate in front of the middle exteriorly; on the 

 supratemporal near the anterior part. The inosculation is honeycomb-like on the parietal, 

 postf rental, and posterior parts of the tabulare." 



MEASUREMENT OF THE TYPE SPECIMEN. 



mm. mm. 



Length of the skull along median line (estimated) ... 60 Length of orbit 9 



Length from muzzle to quadrate angle 71 Width of orbit 8 



Width at posterior border 69 Interorbital width 8 



Width at orbits 40 Length of nostrils 2 



MEASUREMENTS OF ANOTHER SPECIMEN OF THE SPECIES. 

 (No. 8598 G, American Museum of Natural History.) 



mm. mm. 



Median length of skull 56 Length of orbit 7 



Length to quadrate angle 61 Width of orbit 6 



Width at posterior border 50 Interorbital width 4.5 



The specimens of this species were collected by Dr. J. S. Newberry. 



Erpetosaurus obtusus Cope, 1868. 



COPE, Proc. Phil. Acad. Nat. Sci., 1868, p. 213. 



COPE, Trans. Amer. Phil. Soc., xiv, p. 12, fig. I, 1869. 



COPE, Geol. Surv. Ohio, 11, pt. n, p. 396, fig. u, 1875. 



COPE, Proc. Amer. Phil. Soc., 1885, xxn, p. 407 (Pal. Bull. 40). 



MOODIE, Bull. Amer. Mus. Nat. Hist., xxvi, p. 350, pi. Ix, fig. 2. 



Type: Specimen No. 8601 G, American Museum of Natural History. 



Horizon and locality: Linton, Ohio, Coal Measures. 



The species, Tuditanus obtusus, was first described by Professor Cope as Den- 

 drerpeton obtusum, but he subsequently referred the species to the genus Tuditanus. 

 It was removed by the writer to the genus Erpetosaurus in 1909. The species is 

 known from two partially preserved crania. The skull elements seem to have disap- 

 peared and left only the impressions. The sutures are, for the most part, clearly 

 represented, but the skull shows no sculpturing. On the posterior third of one 

 cranium there is a small space which seems to be slightly sculptured, as Cope indi- 

 cated in his drawing. The general form of the skull is that of a broad oval, truncate 

 posteriorly. The orbits lie in the anterior third of the skull, and the pineal foramen 

 in the posterior third. Cope compared the skull to that of Huxley's Erpetocephalus, 

 to which it has some resemblance. The nostrils are elongate and are situated at an 

 obtuse angle with relation to the main axis of the skull. 



The premaxilla is small and forms the inner border of the nostril. There seem 

 to be impressions of small teeth, but no large ones are evident. The nasals are sepa- 

 rated by a zigzag suture, and are nearly square. They have the usual relations. 

 The frontals form a portion of the inner boundary of the orbits and unite behind 



