1904.] Allen, Mammals from Tropical America. 75 



zygomatic breadth 58 ": interorbital breadth, 3 21.3, - 



width of braincase, ' 41, ? 40; length of palate (incisors to end of 

 poir.- :; upper premolar-molar series, $ 20, : 



lower premolar-molar series, * 23, 22; length of lower jaw (front 

 base of incisors to posterior border of condyle), $ 61, $ 60.5; height 

 at condyle, * 30, 2 29; height at coronoid process, $ 43-5, 2 44 

 The dental armature is heavy; the palate is flat (not, or only slightly, 

 depressed at posterior border) ; bullae small and flat. 



Compared with Santa Marta (Colombia) specimens of P. /. 

 megalotus, the general coloration is much deeper and darker 

 throughout, the yellow of a more greenish cast, especially be- 

 low, the tips of the hairs of the dorsal surface black instead of 

 reddish brown, and the narrow dark dorsal stripe, usually 

 well-marked in the Santa Marta specimens, is absent. As 

 regards cranial characters, the skull is considerably larger 

 (about 4 to 6 mm. longer and proportionately wider) , and the 

 teeth are fully one third broader and larger ; the most marked 

 difference, however, is seen in the form of the posterior part 

 of the palatal floor, which is flat in chiriquensis and deeply 

 and abruptly depressed in megalotus, thus greatly reducing the 

 height of the posterior narial opening and giving to it an en- 

 tirely different contour; the pterygoids, on the other hand, 

 are much deeper or broader in megalotus, and the pterygoid 

 hamuli much longer and slenderer; the posterior nares are 

 much broader and shallower, and the audital bullae are much 

 more inflated. 



Potos f. chiriquensis differs greatly in cranial characters from 

 all the South American forms of the genus known to me, but 

 finds a near ally in P. /. aztecus. 



Potos flavus caucensis, subsp. nov. 



Type, No. 14186. $ ad., Castilla Mountains (altitude 6000 feet), 

 upper Cauca region, Colombia, June 9, 1898; J. H. Ba: 



General coloration above yellowish brown, with a reddish tinge and 

 washed with black, with a very prominent black median stripe extend- 

 ing from the shoulders posteriorly to the end of the tail; the hairs of the 

 back are individually brownish gray for their basal two thirds, then 

 broadly ringed with brownish rusty yellow and broadly tipped with 

 black; top of head blackish, as are also the sides and top of nose, and 

 a prominent stripe above and below the eye, forming a broad, nearly 



