1878,] 515 [Cope. 



DlMETRODON GIGAS. Sp. nOV. 



Glepsydrops gigas. American Naturalist, May, 1878, p. 327. 

 This animal is only represented in my collection so far by a large part 

 of the pelvis. This is of the same character as that of the G. natalis, but 

 differs in several details of form and is three times as large in linear meas- 

 urements. The portion anterior to the acetabulum is shorter than in the 

 C. natalis, and relatively deeper. The raised borders of the acetabulum 

 unite, and form a thick obtuse horizontal crest, which continues to the 

 apex, which consists of a broadly expanded shovel-like projection. This 

 symphyseal portion is quite elongate, and carries on its supero-anterior 

 face an obtuse median keel. The opposed elements diverge above the 

 anterior part of the acetabulum. The latter is shallow but entire ; its most 

 prominent borders are the anterior and postero-inferior. 



Measurements. M. 



Length from posterior border of acetabulum forwards. . . .200 



Long diameter of acetabulum 100 



Total vertical diameter to superior border of acetabulum . 155 

 Length of anterior symphysis 175 



Epicordylus erythroliticus. Gen. et sp. no v. 



Char. Gen. Epicordylus is known from a large part of the vertebral 

 column, including all the regions excepting the cervical, so far as at present 

 appears. In general the vertebrae resemble those of Glepsydrops., having 

 well-developed intercentra. The diapophyses are at the base of the neural 

 arch, and are prominent, and with large undivided articular extremity ; 

 they are not present on the caudal vertebrae. The neural spines are com- 

 pressed below and enlarged transversely above, so as to be claviform. 

 They are not elongated over the lumbar or sacral regions, but are similar 

 to those of the dorsal vertebrae at those points. The ossa ilii resemble those 

 of Glepsydrops. The zygapophyses are as usual oblique upwards and out . 

 wards, and the centra are not shortened. 



Gliar. Specif. The centra are a little compressed, and higher than wide. 

 In the anterior caudal region they are a good deal more compressed. 

 The intercentra in a part of the dorsal series are larger than in any known 

 species of Glepsydrops. The neural spines are bilobed at the apex on the 

 sacral region, and become shortly bifurcate on the caudal series. 



Measurements. M. 



Length of a series of seventeen dorsal vertebrae 610 



" an anterior neural spine 050 



" posterior 070 



tubercular costal face of anterior dorsal 020 



" " on seventh vertebrae of 



the series from the last 035 



five caudal vertebrae of probably the same 



animal 180 



Elevation of fourth caudal neural spine 057 



