74 AMPHIBIA AND PISCES OF THE PERMIAN OF NORTH AMERICA 



Cricotus hypantricus Cope. 



Proc. Am. Phil. Soc, vol. xxvii, 1884, p. 30; Trans. Am. Phil. Soc, vol. xvi, 1888, 

 p. 253, plate I, figs. 2-6. 



Type: Several dorsal vertebrae. No. 4552 Am. Mus. Nat. Hist. Cope Coll. 

 From Texas. 



Original description: "This Embolomere is probably represented by tw^o 

 individuals, which are of larger size than any species which have hitherto 

 come under my notice, one of them much larger. It is only the smaller speci- 

 men which is accompanied by the astragalus. Both of them display the 

 hypantropophyses already mentioned in remarks on the genus under the 

 head of C. crassidiscus. (See the original description of the genus.) 



"As already pointed out in the key of species, the dorsal intercentra 

 in C. hypantricus (see description of C. crassidiscus) are stout and not nar- 

 row above, but the thickness increases rather than diminishes upwards. 

 They thus differ from the corresponding intercentra in the C. heteroclitus. 

 In many of the dorsal intercentra the dense external layer which covers the 

 inferior face continues upwards to an apex, the articular surfaces of the two 

 ends meeting so as to exclude the former. This is also the case in the C. 

 crassidiscus. The centra have the abbreviated form characteristic of the 

 genus, and the foramen chordae dorsalis is present, but is smaller than the 

 C. heteroclitus. 



"The supposed astragalus is oblong; proximal border longer than the 

 distal, which is separated by an obtuse angle from the ectad; distal entad 

 not reaching superior surface of bone, long, extending inwards below the 

 revolute proximal part of the entad face, from which it is separated by a 

 narrow oblique groove. Proximal and distal entad separated by notches 

 of the two faces; a ridge the length of the bone below. 



"Measurements. 



"Diameters of centrum of individual with astragalus: M 



Anteroposterior 0.015 



Transverse 028 



Diameters of astragalus: 



Anteroposterior 038 



Transverse 029 



Diameters of centrum of larger individual: 



Anteroposterior 018 



Transverse 03 8 



Diameters of adjacent intercentrum of same: 



Anteroposterior 013 



Transverse 038" 



Revised description: The hyposphene and hypantrum described by Cope 

 are very low down so that the projections appear from the sides of the neural 

 canal and are apparently received into the neural canal of the adjacent 

 vertebra. The neural arch is closely attached to the centrum and in some 

 the suture can no longer be made. The transverse process extends directly 

 out from the neural arch. In some in which the neural arches are lost the 

 side of the centrum is continued up nearly to the edge of the neural canal; 

 in others the facet for the neural arch extends at least one-third of the way 

 down the side. In some vertebrae there is a small facet on the centrum near 

 the lower end, which meets a corresponding one on the intercentrum; it would 

 seem that this facet should be for the capitulum of the rib, but, so far as 



