Cope] 582 i-pj.p jg_ 



The proximal extremity of the quadrate is characteristic, and exhibits 

 features intermediate between those of Liodon ictericits. Cope, and the 

 typical species of Mosasaurus, as M. fulciatus, M. dekayi, &c. The 

 proximal articular face is much like that of M. depj-essus (Trans. Amer. 

 Philos. Soc, 1869, p. 181, Fig. 48, No. 3). The external angle is much 

 smaller than in the Liodons and more anterior, nevertheless it is con- 

 tinued distally as a ridge-like angle sej^arating the antero-lateral from the 

 postero-lateral faces as in them, and not presenting the gradual blending 

 of the two surfaces characteristic of the genus Mosasaiirus. The postero- 

 lateral face is thus flat proximally, and the meatal pit, which is well de- 

 veloped, cannot be seen from the antero-lateral face. The distal part of 

 the quadrate is lost, so that I cannot determine the character of the ridges 

 there. 



The basal element of the axis bears a strong hypapophysis without 

 ai'ticular faces, but very rugose surfaces. The same portion of the atlas 

 is a convex parallelopipedon, with median rugose tuberosity and very 

 rugose extremities. Its surface is not separated from its body anteriorly 

 by a deep groove as in L. ictericus. 



The articular facets of the scapula are much broader than in the other 

 species here described, indicating a head or wider articulation of humerus. 

 No limb bones were preserved. 



The vertebrae are too much injured to be characteristic, with one ex- 

 ception. This one is a posterior dorsal, and had had compressed centrum, 

 or at least not depressed. The inferior face is convex transversely, and 

 there is a slight concavity below each diapophysis. 



Ileasurements. M. 



Parietal, length 0.074 



" width between anterior and crests 048 



" least width 023 



Frontal interorbital width 092 



Quadrate width above 02 



" length from pit to i^roximal end 023 



Articular, length lower edge 015 



" depth in front of cotylus - 35 



" " at end coronoid 055 



Posterior dorsal length 0495 



Scapula proximal width , 051 



This species differs from all those of Mosasaurus and Liodon, in which 

 the form of the qviadrate is known in the character of that bone. From 

 L. laevis and L. congrops in which that element is unknown, it differs in 

 the stouter or less slender vertebrae ; from L. proriger in its much smaller 

 size. 



Its size is a little less than the L. ictericus or L. validus. It is dedicated 

 to Professor Mudge, in recognition of the valuable results of his investiga- 

 tions as State Geologist of Kansas. 



