408 M. R. Thorpe — Leptaiichenia Leidy and 



respect it is more like L. major, altliougii this feature is 

 more pronounced than in the latter species. The bregma, 

 the junction of the sagittal and coronal sutures, is situated 

 considerably farther in advance of the junction of the 

 temporal ridges than in L. decora and holds more nearly 

 the position seen in L. nitida. In L. major the bregma is 

 located at the junction of the temporal ridges. The malar 

 below the orbit is more robust and deeper in this subma- 

 ture specimen than in a fully adult L. decora. The infra- 

 orbital foramen is above the interval between P^ and P^. 

 The bullae are of different shape than in any other species 

 of the genus, but whether this is due to adolescence or not 

 I have no way of determining at present. In outline, they 

 are roughly circular and much inflated. They are pro- 

 portionally as large as in L. nitida, and absolutely larger 

 than in L. decora. They are farther apart, however, than 

 in L. nitida, and their internal faces do not parallel each 

 other vertically as in the latter species. The paramas- 

 toids are broad above and extend downward and consider- 

 ably outward below the inferior edge of the bullae, with 

 which they are in contact for a part of their course. I 

 fail to find this outward direction in the Yale specimens 

 of the three species, in all of which they extend nearly 

 directly downward. The outline of the facial vacuities 

 is partially destroyed, but they were evidently relatively 

 large. 



The ramus is quite robust for a submature animal. The 

 inferior border is very gently curved as in L. decora, and 

 does not turn downward at the angle as in L. major. The 

 coronoid process extends but slightly above the condyle, 

 more as in L. major, and its superior edge does not curve 

 backward, so pronounced a feature in L. decora, but not 

 in L. major. I can not determine this character in L. 

 nitida. The masseteric fossa is unusually deep, and the 

 ramus very robust below the molar series. With respect 

 to the occipital condyles, the external auditory meatus is 

 situated much farther back than in L. nitida, but approxi- 

 mately as in L. major and L. decora, although relatively a 

 little higher. 



Measurements. 



mm. 



Skull, length, oceip. condyles to canine inc 103 



Bizygomatic diam 82 



Diam. of postorbital constriction 22.5 



