Diameters of superior M. I 



Cope.J 1 < ^ [Dec. 16, 



ternally, and is not expanded at tlie base. Tliere is a strong internal 



cingulum. 



A fragment of the lower jaw supports the last two molars. The internal 



angle of the last one, is unfortunately broken. The posterior crest is, 



however, perfectly transverse, which is not the case with the species with 



three posterior tubercles. The preserved part of the posterior border shows 



a distinct, rather narrow heel. The anterior Vs are well developed and 



there are no lateral cingula. The symphysis is flattened out by pressure. 



The inferior canine is large. It is sub-triangular at base and has an anterior 



basal angular projection. 



Measurements. 31. 



-P,. , „ . ,, TTT ( transverse 046 



Diameters of superior M. Ill J , .^ ,. , „„„ 



* I longitudinal 037 



transverse 036 



longitudinal 033 



_. _ ^(Vertical 018 



Diameters crown I. 3 ? , „.,o 



I transverse 018 



^ transverse 038 



Diameters inferior M. Ill < anteroposterior 040 



( vertical in front (restored). . .034 



Length of symphysis 107 



Depth of ramus at M. Ill 056 



The superior molars of this species might readily be taken for an under- 

 sized individual of G. anax, but the last inferior molar is of a different 

 type, and refers the species to a different section of the genus. 



CORYPHODON CURVICRISTIS, Sp. UOV. 



The fragments which represent this species belong to one individual. 

 They include a considerable part of both mandibular rami with numerous 

 molar teeth, and most of the inferior incisors loose. Also the second 

 superior molar, some superior premolars, the canine, and three or four 

 incisors, two of them in place in an incomplete premaxillary bone. None 

 of the bones of the skeleton were obtained, so far as known. 



The ramus of the mandible is both robust and deep. Its inferior border 

 does not rise posteriorly so much as in some species, as e. g., C. latidens, 

 and the angle is well below the horizontal line of the dental alveoli. The 

 dental foramen is just about in this line. The inferior premolars and 

 molars do not differ from, those of several other species, but the last molar 

 has several peculiarities. The external cusp is the only one of the posterior 

 pair which is present. It gives origin to two crests, both of tlieiu curved. 

 The posterior represents the usual posterior transverse crest, but is gently 

 convex backwards, and turns forwards on the inner side of the crown, 

 only terminating at the external base of the anterior cross crest. The 

 other curved crest is low, although higher than in most species, and ex- 

 tends to the middle of the base of the anterior cross crest. There is a dis- 

 tinct heel which is elevated at the middle and disappears gradually at each 

 end, not being abruptly incurved as in C. anax. The anterior part of this 



