173 



extremity which terminates in a thin edge. The form is like that of a nar- 

 rowed radius of -P. iciericus, but it is much too short for the ulna. As it was 

 found with the scapula, it is probably a portion of the fore-limb, and hence 

 may be a metacarpal. A somewhat similar but narrower bone may be a meta- 

 tarsal. A piece which is probably the free hypapophysis of the atlas is a 

 transversely elliptic piece, with an oblicpie smooth articular face at one end, 

 the posterior face rugose, the inferior with a flat truncate process directed 

 downward and backward. If correctly identified, its great peculiarity con- 

 sists in its thinness antero-posteriorly, and the large process. (See PI. xxxi, 



fig- 1 d.) 



In comparing this species with the L. proriger, its nearest ally, I have 

 already observed the difference in the form of the articular surfaces of the cer- 

 vical vertebrae, which are in that species vertically oval, in the present trans- 

 versely so. The comparison is made between posterior cervicals of both, 

 which, in L. dyspelor, are less depressed than the others. As it is possible 

 that the form in the type-example of L. proriger may be slightly affected by 

 pressure, I compare other points. Thus, the palatine bones are more slender 

 anteriorly, and the outer edge descends lowest in a ridge; in L. proriger, the 

 inner is produced downward as a longitudinal rib. In this species, there are 

 eleven teeth ; in that one, nine. The quadrate bone of L. proriger presents a 

 longer internal angle, and more prominent internal ridge, with smaller space 

 inclosed by the basis of the great ala. My statement, in a published letter to 

 Professor Lesley, that the ends of the mandibles were acute, thus differing 

 from L. proriger, is an error, due to my having inadvertently mistaken the pal- 

 atines for the dentaries while writing. The posterior extremity of these 

 bones iu L. proriger is unknown. 



The only species whose dorsal vertebrae are known to resemble, in the 



stoutness of their form, those of L. dyspelor is the L. crassartus; the manifold 



differences of the latter will be at once discovered on reading the description 



already given. 



Measurements. 



ir. 



Atlas, length of the inner articular face ._. - 0.065 



Atlas, length of the posterior articular face 0.054 



Atlas, depth of the posterior articular face 0. 037 



Axis, length at the middle of the side 0.075 



Axis, depth anteriorly ." 1 0. 081 



Axis, elevation of the neural spine 0. 075 



Axis, width of the neural spine (plane) 0.045 



Axis, diameter of the ball, vertical 0. 070 



