Cope. ] 186 [Nov. 2, 
remains. The vertebra which is best preserved, and which may be regarded 
as typical, is probably from the caudal series, and is thus well contrasted 
with the corresponding typical vertebra of the longer known species. 
On this vertebra there is no trace of diapophysis, and the neurapophysis 
rises from the external side of the superior face. The wall of the neural canal 
isnot preserved, but the inference is that the diameter of the latter is large. 
This fact and the absence of definite chevron articulations leads me to doubt 
the caudal position of the vertebra ; but the usual marks of the dorsal and 
cervical vertebree are totally wanting from it. As in C. heteroclitus, the 
foramen chorde dorsalis is large, its diameter being one-third of the total. 
The articular faces descend steeply into it, that of one extremity more so 
than the other. The rim of the latter face is beveled outwards, the plane 
thus produced appearing on the inferior face something like the united 
faces of the chevron bones. 
The centrum is a little deeper than wide, and the inferior face is trun- 
cate so as to give a subquadrate outline. The inferior plane is concave, tie 
concavity being divided by a longitudinal rib. The sides are somewhat 
concave, with a longitudinal rib at the middle. Diameters of centrum : 
vertical .010; transverse .009 ; longitudinal .008. Width of inferior plane 
.005 ; width above, including neurapophyses, .008. 
As compared with C. heteroclitus this species differs in the presence of 
parallel ridges enclosing a median fossa on the inferior side of the centrum. 
The small size may be here considered, but it is uncertain whether the 
two animals represented by thé vertebre are fully grown. 
This reptile is named in recognition of the services of William Gibson of 
Newport, Ia., who has added a number of interesting facts to the geology 
of the Wabash region. 
CRICOTUS DISCOPHORUS, Cope, sp. nov. 
A vertebra, representing an animal as large asthe C. heteroclitus, presents 
characters so much at variance with those of the latter as to require special 
notice. Three other vertebre of smaller size present similar features. 
The centrum is disciform, with very short antero-posterior diameter, 
which is, however, greater at one part of the surface than at the opposite 
point. The foramen chord dorsalis occupies about one-fifth of the trans- 
verse diameter, which is subequal in all directions. The articular faces of 
the centrum are slightly concave. The margin of that of one side is beveled 
for the superior two-thirds of the circumference, the bevel running out 
below by turning into the articular face. The latero-inferior border of the 
latter turns out into an obtuse angle at this point. The superior part of 
the bevel runs into the lateral face of the centrum. The attachment of the 
neural arch is obscure or wanting in the specimen, and the same is true of 
any facet for chevron bones. 
: : BULGE Ae cers cote aie ere le, Se eyareye .025 
Diameter of articular face | vertical 
: GLANS VELSCu eerie + «icicles soo RS 
Length of centrum below........ ehreis eterstetsh 5 wesstotorehenets 009 
Gh ab AMOWV En tre cserenreveterete sevayeveus fats phe tices 007 
