Mammalta of Southern Brazil. 137 
covered with rather stiff hairs, the latter becoming silky towards the 
end of th« tail. 
The spines are generally black on their basal half, and sulphur 
yellow on their terminal half, without other color on the apex 
Those of the interorbital, suborbital and prescapular regions, are 
white, with a black space at the middle, and the base of the spines 
is also white below the black on the posterior regions of the body, 
and on the tail. The hairs covering the basal half of the tail below 
are yellow ; those covering the terminal half are black. End of 
muzzle projecting beyond mouth, covered with minute silky hairs. 
Whiskers long, black. 
Measurements of skin. 
M. 
Total length 665 
Length from end of muzzle to vent 395 
foot on sole (total) 063 
" of third hind claw 018 
Measurements of skull. 
Total length on base 073 
Interorbital width 026 
Length of palate from incisors 032 
Width of palaie below m. iii 010 
In the determination of this species I have had before me in the 
museum of the Academy of Natural Sciences, three specimens of 
-S". villosus Cuv. {S. insidiosus I.icht.), and one each of the F. mel- 
anurus Natt., and the S. nycftthemerus Licht. These render it evi- 
dent that the only species with which it is necessary to compare the 
-S". scriceus is the ^. affinis of Brandt, which I have not seen. That 
animal is described as being brown above and below, instead of 
silvery white, and in having the spines brown tipped. The humeral 
spines are exposed, which they are not in the S. sericeus. Ii is said 
to have a postorbital process of the malar bone. This is wanting 
'n the S. sericeus (two skulls). 
The S. sericeus was probably included by Mr. Hensel in the 
