6 



between the outer cusps of the three last molars. The incisor is com- 

 pressed, the anterior and outer faces being separated by an angle. 



M. 



Length of molars 0140 



" penultimate molar 0033 



Width " " 0035 



" first molar 0030 



Length " " 0035 



Depth jaw at penultimate do 0090 



" incisor tooth 0040 



Width " " 0020 



The skull is broad and stout, but not depressed ; muzzle broad above, 

 short. Front moderately contracted, no postorbital processes. 



GYMNOPTYCHUS NASUTUS, Sp. UOV. 



Much smaller than the last. Inferior molars with two cross-crests and 

 two cingular from the external cones, each posterior crest of a pair ter- 

 ninating in an interior cone. First molar narrower. The anterior part 

 of a cranium probably belongs to the same species. The first molar has 

 a sub-round crown with four tubercles ; the second is constructed like 

 the corresponding inferior. Muzzle much compressed, nasal bones flat, 

 extending to beyond above incisors. 



Measurements. 



M. 



Length anterior three molars 0045 



" first molar 0015 



Diameter inferior incisor 0008 



Depth ramus at second molar 0036 



Length diastema above 0080 



Width at pre-orbital region 0073 



" end of muzzle 0030 



Gymnoptychus trilophus, sp. nov. 

 Ramus depressed, elongate. Molars with two Outer crescents separated 

 by a deep notch, each of which gives rise to a single cross-crest, an 

 anterior and posterior, without cingula. The inner apices of the cres- 

 cents unite and give origin to a short median cross-crest. 



Measurements. 



M. 



Length four molars 0070 



second " 0017 



Width " " 0015 



Depth ramus at second molar 0035 



Width of lower incisor 0010 



Gymnoptychus minutus, sp. nov. 

 A very small species. Middle pair of molars with the anterior and 

 posterior cross-crests bifurcate, and a short median cross-crest. Only 



