THE TEMNOSPONDYLOUS AMPHIBIA. 1 89 



position is near the margin of the anterior articular surface, and the edges of these para- 

 pophyses make the transverse diameter of this extremity somewhat greater than that of 

 the corresponding posterior facet." 



Measurements of the More Perfect Vertebra of Eosaurus acadianus (after Marsh). 



mm. 



Transverse diameter of centrum on anterior surface 59 



Same on posterior surface 57 



Same including the parapophyses 63 



Vertical diameter of anterior surface 34 



Anteroposterior diameter on superior surface 21 



Same on inferior surface 19 



Same between centers of articular facets 2.5 



Length of pits for articulation of neural arch 7 



Breadth of same 7 



Depth of same 2 



Distance between centers of same 11 



Same at centers of parapophyses 36 



Collected by O. C. Marsh at the South Joggins, Nova Scotia. 



Marsh regarded (404) the vertebrae as representing a new type of ichthyosaurian 

 (2), but there can be no doubt that the vertebrae belong to some form of the Amphibia, 

 since the description applies equally well to them. In this connection mention 

 must be made of a large rib from the Linton beds preserved in the U. S. National 

 Museum. Only the proximal third of the rib is preserved, but it represents some 

 large form of the Stegocephala. The rib is strongly curved backward, is heavy, 

 and has an incipient tubercle. A cross-section shows that a longitudinal groove 

 occupies the median line on the exposed surface of the rib. This may, however, be 

 due to compression and thus indicate that the rib was hollow. The rib as pre- 

 served measures: length, 102 mm.; maximum width, 22 mm.; minimum width, 14 

 mm. (Nos. 4490, 4489, U. S. National Museum.) 



Genus EOBAPHETES new name. 



Type: Eobaphetes kansensis Moodie. 



The new name is proposed to replace the generic term Erpetosuchus used for the 

 species E. kansensis described by the writer (Proc. U. S. Nat. Mus., 39, p. 491, 

 1911), and which later was found to be preoccupied by Newton (Phil. Trans. Roy. 

 See. London, 185, p. 573, 1894 b). 



The genus is very readily distinguished by two prominent characters — the short, 

 uniform dentition and the presence of two elongate, oval, internal mandibular fora- 

 mina on the inner side of the jaw. The genus may be further distinguished by the 

 great depth of the posterior portion of the jaw and the slender anterior part, as well 

 as by the ornamentation, which is typically the rough tuberculated labyrinthodont 

 sculpture on the anterior end of the mandible. This changes gradually to longi- 

 tudinal grooves and ridges of a rather small size on the posterior portion, a very 

 unusual arrangement for a labyrinthodont. 



These characters are sustained by those of the skull fragment, in which the den- 

 tition is uniform and the sculpture very similar to that of the mandible. The ribs 

 are long, curved, and solid, as in other labyrinthodonts. 



