175. 



M. 



Ischium, width, proximal 0.085 



Ischium, width, distal 0.075 



Femur, length — 0. 1S5 



Femur, width, proximal 0. 093 



Femur, width, median 0. 064 



Femur, width, distal 0. 130 



Fibula, length 0.116 



Fibula, width, proximal 0. 100 



Fibula, width, distal 0.118 



Fibula, proximal thickness 0. 052 



Fibula, median width 0.080 



Tibia, length 0.103 



Tibia, width, proximal 0. 045 



Tibia, width, median 0.025 



Tibia, width, distal 0.0.32 



Tibia, thickness, proximal 012 



Tibia, thickness, distal ■. 0.030 



Phalange (posterior), length 0. 080 



Phalange, terminal, length 0. 015 



This specimen is one of the most instructive which has yet been dis- 

 covered, including, as it does, fifty vertebras from all parts of the column, a 

 large part of the cranium, with teeth, and both quadrate bones; the scapular 

 arch complete, except back of coracoid on one side; both humeri, radius, and 

 numerous phalanges of fore limb ; the pelvic arch complete, with one hind 

 limb complete to tarsus, with phalanges. The premaxillary is wanting, but 

 the adjacent suture of the maxillary remains. 



Portions of a second individual of this species, or of L. pronger, were 

 found on the Fox Canon. They belonged to a larger animal, one equal to 

 the New Mexican first described. Professor Mudge has fragments of still 

 larger specimens. 



The principal specimen above described was excavated from a chalk 

 bluff". Fragments of the jaws were seen lying on the slope, and other por- 

 tions entered the shale. On being followed, a part of the cranium was taken 

 from beneath the roots of a bush, and the vertebras and limb-bones were 

 found farther in. The vertebral series extended parallel with the outcrop 

 of the beds, and finally turned into the hill, and was followed so far as time 

 would permit. It was abandoned at the anterior caudal vertebras. 



The outcrop of the stratum was light-yellow. The concealed part of the 

 bed was bluish. Yellow chalk left on the specimens in thin layers became a 

 white, or nearly so. The yellow and blue strata are definitely related in most 

 localities, the former being the superior; but in others they pass into each 

 other on the same horizon. 



In instituting a comparison between this and other known MomsauridcB^ 



