SYSTEMATIC REVISION 3I 



Eryops latus Case. 

 Journ. Geol., vol. xi, 1903, p. 394. 



Type: A scapula with the cleithrum attached. No. 182 University of 

 Chicago. From Texas. 



Original description: "The scapula differs from that of Eryops me gacepha- 

 lus in the relatively greater breadth of the coracoidal region and thestraight- 

 ness of the anterointernal edge. The cleithrum is a queerly shaped bone; 

 the posterior end is thin and greatly expanded so that it overlaps the upper 

 portion of the distal end of the scapula and is closely applied to it as a thin 

 scale; it is convex outwardly. The anterior two-thirds of the bone is rounded 

 and rod-like. It lies close to the upper edge of the scapula, but is to be de- 

 scribed as applied to it rather than being articulated with it, for where the 

 bone is broken away the edge of the scapula is smooth and complete. The 

 edges of the rod-like portion of the cleithrum were evidently extended as 

 narrow and very thin wings. The anterior edge is sharp and marked with 

 rugosities where it joined the clavicle, as is indicated in Cope's figure. 

 Broken fragments of the clavicle were found with the scapula and show that 

 the anterior face of the proximal portion was marked with very deep and 

 rugose striations and ridges. The evidence of the cleithrum afforded by this 

 specimen makes our knowledge of the shoulder-girdle of Eryops complete. 



"Measurements of E. latus. 



M 



'Breadth across epicoracoid region o 



Breadth opposite center of face for humerus 



Width of scapula at middle 



Greatest length of scapula 



Greatest length of cleithrum 



182 

 079 

 073 

 371 

 237" 



Revised description: This species is based on the character of the anterior 

 edge of the scapula. In Eryops megacephalus this edge is broadly convex, 

 but in E. latus the edge is flat or concave and it is longer, compared to the 

 length of the scapula, than in E. megacephalus. The species is probably a 

 good one, but needs confirmation. 



Genus PARIOXYS Cope. 

 Proc. Am. Phil. Soc, vol. xvii, 1878, p. 521. 



Type: Two small skulls. Nos. 4309, 4310 Am. Mus. Nat. Hist. Cope 

 Coll. From Texas. 



Origi^ial description: " Suborder Labyrinthodontia . Head of medium pro- 

 portions, with orbits near the middle of the length, and lateral external 

 nares. Epiotic bones prominent, bounding a deep, auditory notch. Man- 

 dibular angle projecting beyond the glenoid cavity. Maxillary and pre- 

 maxillary teeth not large, conic, subequal; within them a series of rather 

 numerous teeth, of near the same size, probably rising from the palatine 

 bone. No lyra discoverable. 



"This genus resembles Rhinosaurus and Eryops, but belongs to the group 

 with prolonged mandibular angle. Among these it differs from Mastodon- 

 saurus and its immediate allies in the deep auditory notch and prominent 

 epiotic bones. From Labyrinthodon and Anthracosaurus, the uniform sizes 

 of its teeth distinguish it; while there is no indication of the facial fontanelle 

 of Dasyceps, which is otherwise much like Parioxys." 



