THE TEMNOSPONDYLOUS AMPHIBIA. l8l 



Eryops sp. indet. Case, 1908. 



CASE, Annals Carnegie Mus., iv,'p. 234, pi. 59, 1908. 



A dorsal vertebra is very probably from this genus. The specimen consists of a 

 nearly perfect vertebra, lacking only the anterior zygapophysis and the upper por- 

 tion of the neural spine (plate 18, fig. 2). It shows no character that would war- 

 rant its separation from the genus, and indicates a medium-sized individual. The 

 zygapophyses have clean-cut articular faces. The pleurocentra are thickened above, 

 with just well-defined articular faces, which were applied to faces on the neural arch 

 posterior to the origin of the transverse process. The intercentrum is of the familiar 

 half moon-shape, thick and heavy below, and thinner toward the extremities; the 

 anterior edge is marked near the top by the indentation found on the intercentra of 

 Eryops. 



Height of the vertebra from the middle of the lower face of the intercentrum to 

 the middle of the neural canal, 0.035 m - ; width of intercentrum 0.026 m. 



The second recognizable specimen is a neural spine from the caudal series. This 

 is without question a portion of the skeleton of an Eryops. Similar spines were 

 described by Cope as Eryops (Epicordylus] erythrolithicus , but later discoveries 

 seem to show that similar characters occur in other species of the genus as well. The 

 apex of the spine is bifurcate; the space between extremities is concave and per- 

 fectly smooth ; below the sides of the spine are rather rugose and marked with ridges. 

 The lower portion of the spine is elongated anteroposteriorly and the edges are 

 marked with sharp, double ridges. 



Three ribs also belong, in all probability, to the genus Eryops. The head of 

 each rib is broad and the articular edge is divided between two faces which meet at 

 an angle somewhat greater than a right angle; the two faces are continuous. The 

 shaft is somewhat flattened and in the undistorted specimens is gently curved. The 

 length of the largest rib is about 0.07 m. 



Other than these specimens there are several small intercentra (94) and the 

 neural spine of a caudal vertebra from some undetermined amphibian. 



Family MACRERPETID^E Moodie, 1909. 



MOODIE, Bull. Am. Mus. Nat. Hist., xxvi, art. xxv, p. 354, pi. lix, fig. i, 1909. 



It has seemed necessary to propose a new family for the reception of the single 

 species Macrerpeton (Tiiditanus) huxleyi Cope. The characters exhibited by this 

 species are so different from those offered by other members of the Carboniferous 

 Microsauria that it is clearly distinct. In its cranial characters and the position of 

 the orbits it approaches most nearly to Eryops megacephalus Cope from the Per- 

 mian of Texas. In some of its characters the present form shows a similarity to 

 Dasyceps bucklandi Lloyd (324), from the Permian of Kenilworth, England; more 

 especially is this similarity found in the form of the skull, the size and shape of the 

 teeth, and the posterior position of the orbits, and their wide removal from the 

 border of the skull. Only a fragment of the skull has hitherto been known, but re- 

 peated study of this fragment (123) has disclosed the wide diversity (462) of its 

 characters. An almost complete skull, described below, substantiates the charac- 



