12 CONTRIBUTIONS TO PALAONTOLOGY 
orangs reveals a marked inferiority in length of M3 as compared with M3. 
In any case the occlusal relations between the new palate and the type 
mandible of cautleyi strongly suggest specific identity. 
The restoration of the mandible and upper dental arch (pl. 4B, C) was 
made by one of us (M. H.) according to the following steps: 
1. The type of Dryopthecus mlgrimi includes the uncrushed, beautifully 
preserved front end of the mandible; this so closely matches the front part 
of the lower dentition in the type of Dryopithecus cautleyi that the two 
forms may safely be assumed to be closely related or identical. 
2. From these two specimens, the left side and the front end of the lower 
dental arch being given, the missing parts on the right side were modeled 
as mirror images of the known parts. This gave the diameters across the 
canines, premolars, and molars. 
3. The several missing upper cheek teeth of No. 617 were modeled as 
mirror images of their fellows of the opposite side. 
4. The individual upper teeth of one side of No. 617 were placed in series, 
according to the evidence afforded by the interproximal wearing facets. 
5. The opposite upper teeth were placed at such transverse distances from 
their fellows as would allow them to occlude with their antagonists on the 
restored mandible. 
6. A preliminary placing of the upper dental arch having been tried, minor 
corrections in the positions of the individual teeth were made by a process 
of trial and error, until all the upper teeth were in correct occlusal relations 
with their antagonists in the lower jaw. 
7. The positions of missing lower incisors were given by their well- 
preserved roots; the collective width of their crowns was fixed by the known 
distance between the mesial sides of the opposite canines. 
The fact that the palatal arch as thus built up does fit with considerable 
accuracy on the lower teeth is taken as experimental evidence that the 
upper and lower teeth belong to the same species. 
The upper premolars and molars seem to agree in generic characters with 
those of the type of Sivayithecus orientalis Pilgrim (= S. indicus), while 
the lower cheek teeth agree generically with the type of Sivapithecus hima- 
layensis Pilgrim, as well as with Pilgrim’s original type of S. indicus (Ind. 
Mus. D 177). For this and other reasons we conclude, provisionally at 
least, that Dr. Pilgrim was correct in referring the types of the species 
named by him Sivamthecus himalayensis and S. orientalis to the genus 
Sivapithecus. 
The upper and lower canines by their contrast in dimensions correspond 
to the differences between male and female orangs. The more slender, much 
worn canine (K 23/212, pl. 2, figs. la, 16, A, B) occludes very well with 
the lower canine and anterior premolar of the type of Dryopithecus 
cautley2. 
No. K 29/466, the smallest upper canines (right and left) are associated 
with right and left upper premolars and molars which we have likewise 
referred to sitvalensis. These canines (pl. 1, figs. la-ld; pl. 2C, D, E) have 
the “premolar characters” greatly emphasized, namely, relatively low tip, 
marked anterior vertical groove bordered by prominent vertical lingual and 
buccal ridges, conspicuous internal cingulum culminating in large lingual 
tubercle, pronounced posterointernal fossa, sharp posterior cutting edge. 
Nevertheless we tentatively refer this to the same species (sivalensis) as 
the slender crowned canine (K 23/212) because these differences can be 
closely matched among female orangs (A.M. 19548, 18010). 
