1880.] MR. O.THOMAS ON MAMMALS FROM ECUADOR. 399 



they slightly diverge behind in B. alleni. (5) The last upper 

 molar, instead of being subquadrate, as long as it is broad, and nearly 

 as large as the first, is subtriangular as in Procyon, much broader 

 than long, and consideral)ly smaller than the first molar, as shown 

 in the table of measurements. (6) The top of the coronoid process of 

 . the lower jaw (see fig. 3) is different in shape from that of B. gabbi ; 

 and in the latter the angular process is further from the condyle than 

 in B. alleni. 



When the external characters of B. gabbi are described, I feel 

 quite sure that further points of difference will be found between 

 these two forms from such very distant localities as Costa Rica and 

 Ecuador. 



The skull of Bassaricyon is so absolutely different from that of 

 Cercoleptes that Mr. Allen did not think of comparing tlie two ; and 

 I fully agree with him in thinking this animal more nearly allied to 

 Procyon and Nasua than to any of the other Procyonidse, though in 

 size it is more similar to Bassaris. 



Fig. 3. 



Lower jaw of ^^ i/on alleni. 



The external resemblance of this species to Cercoleptes certainly 

 seems to be an instance of mimicry, which, so common among in- 

 sects, is somewhat rare among Mammalia. It is, however, very 

 difficult to understand how being mistaken for Cercoleptes could in 

 any way benefit Bassaricyon ; but when more of the habits of the 

 latter are known we may hope to be able to guess at the true use of 

 the likeness. 



Mr. Buckley unfortunately did not take any especial notice of the 

 habits of this animal, as both he and the Indians thought it to be 

 merely the common Kinkajou. It is much to be hoped that more 

 specimens of this interesting genus will be found ; and I would draw 

 the attention of collectors and others to the only external means of 

 distinguishing it — namely, the flatness of the head and the greyness 

 of the face as compared with the high head and yellowish face of 

 the Kinkajou. 



