1893-] Allen and Chapman on Trinidad Mammals. 



225 



characters it differs at many points, but it may be sufficient to 

 mention the much greater posterior extension of the nasals, 

 which extend much beyond the fronto-maxillary suture instead 

 of terminating considerably in front of it, as in E. cayannensis, in 

 which the axis of this suture is oblique instead of transverse. In 

 other words, the nasals and the direction of the fronto-maxillary 

 suture are about as in E. brevicauda, as figured by Gtinther (P. Z. 

 S., 1876, p. 749). In this respect it also much resembles E. semi- 

 spinosus Tomes, from Ecuador, from which species, however, it 

 differs in its very much larger and very differently shaped ears 

 and much longer tail. It appears to resemble this latter species, 

 however, in the restriction of the spines to the central portion of 

 the dorsal area, in the naked and tuftless tail, and in general 

 features of coloration. 



The adults present very little variation in coloration or in ex- 

 ternal characters beyond that already noted, except that three of 

 the adults were entirely tailless, the loss of the tail having evi- 

 dently occurred in early life, leaving only a broad cicatrix where 

 the tail joined the body. The young specimens are also quite 

 uniform in general coloration, except that in three there is a 

 broad dusky prepectoral collar, varying in width in different in- 

 dividuals, and represented in others by a broken collar, the two 

 halves failing to meet on the median line. 



The principal variations in external measurements in ten adult 

 specimens are shown by the following table : 



External Measurements. 



1 Alcoholic. 2 Tail wanting. 

 [September, i8gjJ\ 



3 Body destroyed by some predatory bird or mammal. 



15 



