74 Bulletin American Museum of Natural History. [Vol. XX, 



become complicated through Mr. Thomas's use of Martin's 

 practically baseless name megalotus for "Costa Rica and 

 Colombia" specimens collectively. I should discard megalo- 

 tus as unidentifiable were it not that Thomas has habilitated 

 it, and so under the 'first reviser' principle it may be con- 

 served for a portion of the Costa Rica-Colombia combination. 

 As most of his specimens were from Colombia, a Medellin 

 example being particularly mentioned as agreeing "best with 

 the description," and Valdivia and Santa Marta (Colombia) 

 specimens "cannot be distinguished from it," it seems best to 

 assign the name megalotus to the form of eastern Colombia; 

 especially as my Santa Marta specimens agree far better with 

 the description of megalotus than do those from Chiriqui. 

 The additional three forms may be recognized as follows : 



Potos flavus chiriquensis, subsp. nov. 



Type, No. 18926, $ ad., Boqueron, Chiriqui, Panama, Oct. 22, 1901 ; 

 J.'H. Batty. 



General color (type) above brownish yellow, the hairs individually 

 being dull brownish yellow, tipped conspicuously and quite uniformly 

 with blackish; middle of the back rather more blackish than the 

 sides, but without a dark dorsal line; below dull greenish yellow (with- 

 out black tips to the hairs), with a darker rusty brown streak along 

 the middle of the abdomen; sides of neck, from shoulders to cheeks, 

 and front of neck, yellowish rufous or golden rufous; ears colored like 

 the surrounding pelage; tail above like the back for about four fifths 

 of its length, becoming gradually darker or brownish black apically on 

 the terminal fifth, the sides and below dull brownish yellow. 



Six other specimens differ scarcely appreciably from the type; in 

 two there is a slight tendency to a dark dorsal line. 



Measurements. The collector's measurements are as follows: 



No. Sex. Total length. Head and body. Tail vertebrae. Hind foot. Ear. 



18926 $ type 990 485 505 80 42 



10122 * $ 960 460 500 93 40 



18925 $ 815 390 425 75 36 



18924 9 975 480 495 75 40 



18923 9 juv. 747 350 397 80 40 



Two adult skulls, No. 18926, male (type), and No. 18924, female, 

 measure as follows: Occipito-nasal length, $ 92, 9 90; basal length 

 (inner base of incisors to posterior border of condyles), $ 83, 9 82; 



1 Bangs Collection. 



