193 THE COAL MEASURES AMPHIBIA OF NORTH AMERICA. 



MEASUREMENTS OF LEFT RAMUS OF MANDIBLE OF EOBAPHETES KANSENSIS MOODIE. 

 (Cat. No. 6680, U. S. Nat. Mas.) 



mm. mm. 



Total length of jaw, as preserved 305 Length of anterior internal mandibular foramen. ... 56 



Greatest width 79 Greatest width '15 



Least width 24 Least width 7 



Length of angular ... 132 Length of posterior internal mandibular foramen. . 77 



Width of angular 45 Greatest width 28 



Length of largest tooth 10 Least width 14 



Width <>f largest tooth at base . . . 6 Length of bridge 16 



Length of most posterior tooth ... 6 Width of bridge .... 8 



Width of most posterior tooth at base 4 



R-ibs. There are portions of two dorsal ribs preserved on the block of coal with 

 the skull. These show characters very similar to those exhibited by the rib ascribed 

 to Mdcrcrpcton Inixleyi Cope, and also those of Metoposaurus diagnosticus von Meyer 

 (242) and Aimschisma. The ribs are solid, heavy, curved, and have a longitudinal 

 groove on the middle of each side. The heads of the ribs in the present specimen are 

 obscured and nothing can be said of them except that they appear to be large. 



MEASUREMENTS OF RIBS OF EOBAPHETES KANSENSIS MOODIE. 



mm. 



Length of preserved portion 130 



Width at distal end 1 8 



Thickness of rib 5 



Genus DENDRERPETON Owen, 1853. 



OWEN, Quart. Jour. Gcol. Soc. London, ix, p. 66, 1853. 



Type: Dcndrcrpeton acadianum Owen. 



The genus is characterized by Dawson as follows (Phil. Trans., 1882, p. 635): 



" Lizard-like, with anterior and posterior extremities nearly equal; the skull somewhat 

 elongate with small orbits, and the nostrils placed at the front. The cranial bones sculp- 

 tured. The teeth plicated at the base, more especially on their inner sides. A series of large 

 teeth on the palate. The body was covered above with imbricated horny scales and had 

 lappets or pendants at the sides. The abdomen was protected by thin bony scales semi- 

 elliptical or oat-shaped in form, and arranged in a chevron pattern. There was probably 

 also a thoracic plate. Two species : D. acadianum and D. oweni. 

 'Type: D. acadianum Owen." 



Dendrerpeton acadianum Owen. 



OWEN, Quart. Jour. Gcol. Soc. London, ix, p. 66, 1853. 



DAWSON, Air-breathers of the Coal Period, p. 17, 1863. 



DAWSON, Acadian Geology, 3d ed., p. 362. 



DAWSON, Phil. Trans. Roy. Soc. London, pt. n, p. 642, pi. 40, figs. 46 to 51; pi. 44, figs. 129 to 137. 1882. 



Type: Specimens Nos. 434-438, British Museum of Natural History. 

 Horizon and locality: Coal formation at Sot;th Joggins, Nova Scotia. (Plate 6.) 

 This species has been fully described and figured by Dawson (Air-breathers of 

 the Coal Period, pp. 17-30, pi. in, figs, i to 30, 1863), who gives a detailed account 

 of the discovery of the material of this species by himself and Sir Charles Lyell. 

 He says, in part : 



"In form, Dendrerpeton acadianum was probably lizard-like; with a broad flat head, 

 short, stout limbs and an elongated tail; and having its skin, and more particularly that of the 

 belly, protected by small bony plates closely overlapping each other. It may have attained 

 the length of 2 feet. The form of the head is not unlike that of Baphetcs, but longer in pro- 



