I6 4 



THE COAL MEASURES AMPHIBIA OF NORTH AMERICA. 



ftpo 



is probably a small element, especially if the lacrimal is present. There seems to 

 be an indication of a suture separating the lacrimal from the prefrontal, but this 

 character is not assured. The boundaries of the maxillae are clear anteriorly. They 

 indicate that this element was elongate, as is usual, and impressions of teeth borne 

 on the mandible would indicate the probability that the teeth were heterodont. 

 In the premaxillary region there is a long, strong tooth preserved, and on the max- 

 illary near the posterior ex- 

 tremity of this bone there are 

 impressions of teeth which are 

 no more than one -fourth as 

 large as the premaxillary one. 

 The borders of the jugal can 

 not be ascertained, since the 

 skull is injured on both sides 

 in this region. Likewise the 

 quadratojugal is conjectural. 

 The boundaries of the post- 

 frontal and the postorbital are 

 clearly ascertained. They to- 

 gether form the entire poste- 

 rior border of the orbit and 

 send prolongations along the 

 lateral borders of these open- 

 ings. They are both acumi- 

 nate posteriorly and these 

 points are inclosed by the tab- 

 ulare and supratemporal for 

 the postfrontal and by the 

 squamosal and prosquamosal 

 space for the postorbital. The 



show this element to be quite 

 large and extending forward 



j. 35. Outline drawing of the skull and skeleton, as preserved, of 

 Saurerpetun lalithorax (Cope), from the Linton, Ohio, Coal Measures. 

 . . r , Original in U. S. National Museum. X 0.75. 



boundaries OI the tabulare Skull: /r, frontal; j, jugal; mx, maxilla; 11, nasal; no, nostril; or, orbit; 



par, parietal; pof, postfrontal; po, postorbital; pp, postparietal; pf, 

 prefrontal; pmx, premaxilla; qj, quadratojugal; m, mandible; spa, 

 supraorbital lateral-line canal; spt, supratemporal; sg, squamosal; 

 tab, tabulare; y, pineal foramen. 

 llltO an aCUminatlOll Which is Skeleton: r/, clavicle: c, carpus; rb, ribs; 7i, humerus; ic, interclavicle; 

 . ... met, metacarpals; psc. pectoral seutelke; r, radius ;vs, ventral scutelhc; 



inclosed by the parietal and u , ulna. 



the postfrontal. The sutures bounding the squamosal have been obscured by injury 



in removing the specimen and are indeterminable. 



The vertebral column is represented by a ridge showing along the median plane 

 of the specimen. Its characters can not be ascertained. There are a few evidences 

 of ribs. They represent long, slender, non-alate elements, their mode of articu- 

 lation with the vertebras being obscured by the plate-like ventral armature which 

 covered the abdomen of the animal. 



The pectoral girdle is represented by the remains of three elements which are 

 interpreted as being the interclavicle and the two clavicles. The interclavicle is 

 broad and is rounded posteriorly. There is no evidence of the usual acumination 



