SYSTEMATIC REVISION 'j'^ 



The measurements of the C crassidiscus are as follows: 



"Measurements. 

 "Diameters of dorsal centrum behind; M 



Vertical 0.025 



Transverse 025 



Length of do.: 



Middle line below 013 



At base of neural arch 013 



Base of neural arch : 



Width 010 



Length 009 



Diameters of a dorsal intercentrum: 



Vertical 025 



Transverse 025 



Length of do. : 



Middle line below 009 



Middle line above 0095 



Diameters of coracoid, transverse length 027 



Diameters of coracoid, width : 



Glenoid face 029 



Internal face 010" 



See also quotation from same paper in original description of the genus. 



In the second paper cited, Cope described as C. heteroclitus a specimen 

 with the skull, which he later made the type of this species. It was regarded 

 by him as a single specimen, but turns out to contain parts of two animals : 



"Specimens of a number of individuals probably referable to the above 

 species, exhibit many of its characters. These are very remarkable, and 

 indicate another type of vertebral column heretofore unknown. 



"The intercentra are more largely developed than in any other genus, 

 having the form and proportions of the centra in the caudal region, and 

 being but little smaller in other portions of the column. In the prepelvic 

 region, the true centra only bear neural arches, which are articulated, and 

 bear short diapophyses at their base. In the caudal region they share the 

 neural arches with the intercentra, while the latter bear the continuous chev- 

 ron bones exclusively. The neural spines are well developed, and not pro- 

 longed, in both regions. The ribs are robust, and the abdomen is protected 

 beneath by a series of long, narrow and flat scales, which form imbricated 

 chevrons directed forwards at the middle line. 



"The phalanges are short and wide, with but slightly condyloid articu- 

 lations. The distal one is very short, and terminates in a narrowed obtuse 

 projection, somewhat like those of man, but shorter. 



"A cranium which accompanied the portions of the trunk above de- 

 scribed, may belong to the same species. It is that of a Labyrinthodont in 

 some degree allied to Trematosaurus. Its form is elongate and the orbits 

 are behind the middle. The mandibles do not exhibit prominent angles, 

 and the epiotic angles are not distinguished by a notch from the posterior 

 border of the os-quadratum. The epiotic bones and two supraoccipitals 

 form the posterior boundary of the table of the cranium, anterior to which 

 the usual parietals and pterotics extend to the frontals and post-frontals. 

 Below the latter is the post-orbital, which is bounded behind by the squa- 

 mosal (supra-squamosal, Owen, Paleontology, p. 176). The quadra tojugal 

 is possibly distinct from the large malar. There is a lyra of two grooves, 

 which are widely separated on the anterior part of the muzzle, and which 

 converge in front of the orbits, which they barely reach. Another groove 



