338 STNOPSIS OF THE VERTEBRATE FAUNA OF THE PUEKCO SERIES. 



cusp is a small cone, and is not spread away from the fourth and connected with it 

 by a crest, as in 0. steno'ps. In specimens with the last inferior molar preserved, that 

 tooth is seen to be of average proportions. 



The brain-case is long, narrow and rather low, and the sagittal crest is low and 

 thin. It does not in the least resemble that of Adapis, but is rather that of a Creo- 

 dont. Post orbital region lost. 



3Ieasurements. M. 



Length of five superior molars 031 



anteroposterior 0055 



Diameters p. m. i , „„__ 



transverse 0055 



f anteroposterior 007 



Diameters m. ii^^ „„„_ 



(^ transverse 0085 



( anteroposterior 0055 



Diameters m. iii - 



I transverse 0875 



f anteroposterior 007 



Diameters inferior m. ii < „„„ 



I transverse 00G5 



f anteroposterior 006 



Diameters m. i \ 



I transverse 006 



Depth of ramus at m. i 013 



Cheiacds sculosserianus sp. nov. 



Parts of four individuals represent this species. Three of these are from the 

 Upper Puerco ; the exact horizon of the fourth is probably the same, as those from 

 the Lower Puerco are especially marked in my collection. The typical specimen in- 

 cludes jjarts of both maxillaries with molars ; both mandibular rami, one nearly per- 

 fect and sujjporting the last foyr molars ; parts of both humeri, an ulna and part of 

 the right astragalus. The species is smaller than the C. i^viscus, and has about the 

 dimensions of the MioclcBuns suhtrigonus. 



The posterior internal cingular cusp of the second superior molar is better devel- 

 oped than in the Cjiviscus, but nothing like that seen in the C. pelvidens and C trun- 

 catus. The cingulum continues round the internal side of the crown in the second 

 and third molars (first injured). External cingulum present. Last molar of rela- 

 tively small size, about as in Mioclcenus turgidus, but larger than in Tricentes ince- 

 quidens. Internal cusp of p. m. i small. The inferior series is distinguished by the 

 small size of the third. The anterior part of the crown of the inferior molars has 

 a distinctive character. The fifth cusp is not distinctly defined, but the anterior part 

 of the crown forms a three-side prism, the anterior edge, oi- that connecting the ex- 

 ternal anterior cusp with the lifth, being vei-y well defined. On wearing, the summit 

 forms a narrow V with the apex external. External cingulum complete on the 

 second true molar only. The first premolar is of moderate size, and has an anterior 



