66 SMITHSONIAN MISCELLANEOUS COLLECTIONS [vOL. 45 



lessened by admixture of black hairs. It may be traced however to 

 extreme tip, which is also grayish. The gray of the tail is somewhat 

 washed with pale buff. 



Skull and teeth. — The skull of Presbytes batuanics is smaller than 

 that of P. suniatraiiiis and its width is greater in proportion to the 

 length. The orbits are better defined from outline of braincase 

 above, and the frontal region is less swollen. Teeth as in Presbytes 

 sumatranus, but uniformly smaller. 



Measurements. — External measurements of type : total length, 

 1 1 50; head and body, 485 ; tail vertebrae, 665 ; foot, 163 (161). 



Cranial measurements of type : greatest length, 90 (96.4) ;^ 

 basal length, 64.6 (69) ; basilar length, 59 (65) ; median palatal 

 length, 29 (30) ; palatal breadth between front molars, 17.4 (18) ; 

 zygomatic breadth, 72 (73) ; mastoid breadth, 58 (62) ; greatest 

 breadth of braincase above roots of zygomata, 52.6 (56) ; least 

 breadth of braincase immediately behind orbits, 41 (43) ; greatest 

 orbital breadth, 61.4 {62) ; least distance from orbit to alveolus of 

 inner incisor, 17 (21) ; greatest depth of braincase, 42.6 (44.6) ; man- 

 dible, 64 (66.6) ; maxillary toothrow exclusive of incisors (alveoli), 

 28 (29) ; three upper molars together (crowns), 16.8 (16.8) ; man- 

 dibular toothrow exclusive of incisors (alveoli), 33 (32) ; three lower 

 molars together (crowns), 18.4 (17). 



Specimens examined. — Ten, all from the Batu Islands. 



Remarks. — The Batu Presbytes is readily distinguishable from 

 its Sumatran representative by the smaller general size, and par- 

 ticularly by the shorter tail. Of four adults of the latter from 

 Tapanuli Bay none has the tail less than 730 mm. in length, while 

 among the nine adults of Presbytes batuanus the longest tail is only 

 710 mm. The series shows no variations worthy of special note. 



SIMIAS gen. nov. (Cercopithecidae). 



Type. — Simias concolor sp. nov. 



Characters.— S^wW essentially as in Nasalis, but rostrum less pro- 

 duced and nasals not as wide. Nose like that of Rhino pithecus. 

 Tail about one-third as long as head and body, naked except for an 

 inconspicuous tuft of hair at tip. Ischial callosities large and con- 

 spicuous. Teeth as in Nasalis, Rhino pithecus, and Presbytes. No 

 cheek pouches. 



Remarks. — This genus combines the more important structural 

 characters of Nasalis and Rhinopithecus with an external form un- 



1 Measurements in parenthesis are those of an aduh male Presbyter 

 sumatranus from Tapanuli Bay, Sumatra (No. 114,507). 



