Il6 THE COAL MEASURES AMPHIBIA OF NORTH AMERICA. 



provided with tabulate comua and a broad backwardly directed process; quadrate 

 angle does not project on the border of the skull ; sculpture of the cranial elements 

 impressed as radial grooves; 12 presacral vertebrae, i sacral with expanded neural 

 spine which is sculptured at the top, with simple long, apparently separately ossi- 

 fied transverse processes; extremities small; foot with s digits; phalangeal formula 

 2-3-3-4-3- 



The most important differences between Diceratosaurus and Ceraterpeton, the 

 most nearly allied genus, is (in Diceratosaurus) in the more anterior position and 

 small size of the orbits, the backward extension of the quadrate region, and the 

 dorsal expansion of the vertebral spines. A further, and more important, difference 

 between the genera is in the location of the backwardly directed processes from the 

 skull. In Ceraterpeton they project backward from and are a portion of the tabulare 

 element, while in Diceratosaurus the projection consists almost entirely of squa- 

 mosal and supratemporal. 



Diceratosaurus punctolineatus Cope. 



Cope, Proc. Phila. Acad. Nat. Sci., 1875, p. 16. 



Cope, Geol. Surv. Ohio, n, pt. n, p. 372, pi. xli, fig. 4, 1875. 



MooDiE, Bull. Am. Mus. Nat. Hist., xxvi, art. xxv, p. 356, pi. Ixv, 1909. 



Type : Specimen No. 8606, American Museum of Natural History. 



Horizon and locality: Linton, Ohio, Coal Measures. 



The species was first described by Cope as Ceraterpeton punctolineattcm (122). 

 It was redescribed on more abundant material (plate 19) by Jaekel (347), and the 

 following is taken from the discussions of these two authors, checked by my own 

 observations on the type specimen. This shows a portion of the skull, consisting 

 of the squamosal and supratemporal with a projecting, convergent horn. The 

 sculpturing on the skull is similar to that on the pectoral plates, of which there are 

 three preserved (plate 14, fig. 4). The bones of the fore limbs are stout and 

 short. The ribs are only slightly curved. The character of the vertebrae can not 

 be ascertained. The sculpturing of the bones consists of radiating ridges, grooves, 

 and pittings. 



Jaekel (347) described from the museum collection at Berlin 3 specimens of 

 this species, among which were 2 skulls. There were associated with these remains 

 some pectoral plates and limb bones with a nearly complete series of vertebrae. A 

 modified translation of Jaekel's description follows: 



The skull of the largest specimen has, including the horns, a length of 35 mm. 

 and a width of 30 mm. on the occipital border. From the anterior end to the pos- 

 terior border of the skull (exclusive of the horns) there is a length of 25 mm. The 

 pineal foramen lies about midway of this length. The orbits are rather large, al- 

 most circular, and lie about midway between the pineal foramen and the anterior 

 border of the skull. The nostrils, which lie anterior to the orbits, are a rather oblique 

 oval and narrowed on the lateral ends. The distance between them is about the 

 same as that between the orbits, which measures 7 mm. 



The skull roof is sculptured with pits much like those of Archegosaurus. The 

 larger the bones, the rougher the sculpture. The bones of the middle of the skull 

 (that is, the parietals, frontals, premaxillae, nasals, and postparietals) are of the 



