77(1 MONOGRAPHS OP NORTH A.MERIOA.N RODENTIA. 



to S. langsdorffi of three of the specimens there mentioned. He says fur- 

 thermore that he believed the large Squirrels of Brazil were referable to 

 several species,* which he in this paper attempts to characterize. The dif- 

 ferences he mentions, however, either in size or color, are by no means im- 

 portant, in view of the usual range of variation presented by the American 

 Sciuri. lie restricts, however, the 8. langsdorffi to specimens strictly refer- 

 able to Brandt's original description, or those having the dorsal surface varied 

 with ochre-yellow and black, and the lower parts ochry-rust-yellow, with a 

 small spot of white on the throat ; the lore limbs pale yellow, sprinkled with 

 black; the hind limbs similarly colored, bid more reddish; the tail black at 

 the base, mixed with pale yellow, passing toward the end into orange-red. 

 The nine examples he refers to this species"he says are all of the same color, 

 and all come, according to Natterer, from Cuyaba, in the province of Matto 

 Grosso, Brazil. According to his measurements, this species is the smallest 

 of the four he here recognizes. 



The seven specimens he refers to S. igniventris are all from Marabita- 

 nas.'on the Upper Rio Negro. Four of them are red, the remaining three 

 black. Two of the red specimens have the hairs of the back black, with 

 light points, which in one are reddish-yellow, in the other grayish-yellow; 

 so that in one the dorsal suidace is rust-red sprinkled with black, in the other 

 rust-yellow sprinkled with black. The under side of the body is beautiful 

 rust-red. The tail is black at the base, but mostly red at the surface, with 

 the hairs black basally, somewhat mixed with yellow. The size is given as 

 a little larger than that of S. langsdorffi. This species he says differs from 

 both S. langsdorffi and S. pyrrhonotus through its color and its habitat, and 

 from the former also in size. 



The nine specimens of S. pyrrhonotus were (except one) all collected 

 by Natterer near tin 1 mouth of the Rio .Madeira. The color above is lively 

 rust-red, inclining anteriorly more to orange-red and posteriorly becoming 

 fiery-red ; below, whitish-yellow or ochre-yellow, lightest anteriorly. The 

 tail is. as in the other species, black at the base, passing into rust-red or rust- 

 yellow, with the hairs broadly black at the base. The eight specimens col- 

 lected by Natterer are said to be all of the same color: the ninth, from Spi\'s 



Sei'dem babe ich mm die- gauze Sammlnng von Natterer vergleicherj kojnen nnd bin dadnrch 



mil ilmi zur I VImi z aguDg gelailgt, doss nicbl our limine I! vorhin genanntea Exemplars gar rjicht dem 



us langsdorffi angeboren, Bondern das.s uuter den grosseu brasilischen Eichhurnehen nu-hrere Arten 



zu untersebeiden seyen, wie ich dies nun auseinander setzeu will." — (Abhandl. ier maih.-pliytik. Classe 



Bayer. .Had. der Wissensck. v, 274.) 



