760 MONOGRAPHS OF NORTH AMERICAN RODENTIA. 



although in size and coloration it. agrees perfectly with the descriptions of 

 N. pusillus* 



The next synonym of the Brazilian Squirrel (var. cestuans) is the & gil- 



vigularis (Nat trier, MS.), a species first described by Wagner in 1813, based 

 on specimens from the mouth of the Rio Madeira, having the chin and throat 

 ochre-yellow. This form he regarded as the northern representative of the 

 S. cestuans of Southern Brazil. In 18G3, Peters gave the varietal name 

 guianensis to specimens from British Guiana, also immature, though much 

 larger than the S. pusillus of Geoffroy. Two of the numerous nominal species 

 (1. 'scribed by Dr. Gray, namely, S. Jlaviventer and <S. kuhlii from "Brazil", 

 arc also undoubtedly referable -to var. astuans, as is also his M. leucogaster 

 from Eastern Bolivia. 



The first name applicable to the northern form of Sciurus cestuans seems 

 to be the rufoniger of Pucheran, given in 1845 to specimens from Santa FY- de 

 Bogota. In the same article, the name chrysurus was given to other speci- 

 mens from the same locality. The first name was applied to examples having 

 the middle of the body dark, the sides reddish, the chin and throat gray, and 

 tin; tail ringed with red and black; the second to specimens with the dorsal 

 surface uniformly colored, the throat yellow, and the tail washed with golden. 

 To the extreme phase of this species, as developed in Costa Rica, Peters, in 

 1864, applied the varietal name hoffmanni {Sciurus cestuans var. hoffmann'i), 

 in which the size is rather larger and the colors stronger, especially the rufous, 

 than in the New Granada specimens. Gray's Sciurus hyporrhodus, described 

 in 18G7, was based also on specimens from Santa Fe de Bogota, apparently in 

 full winter pelage, which are unquestionably referable to the form previously 

 named by Pucheran. His description applies in every detail to numerous 

 specimens before me from Costa Rica. Gray's Macroxus irroratus, from the 

 Upper Ucayali, Eastern Peru, also belongs here, showing that this rufous 

 form of Sciurus cestuans ranges quite far southward along the eastern base 

 of the Andes. [ also refer to this form the same author's M. griseogena from 

 Mexico, Honduras, Costa Rica, Panama, and Santa Fe de Bogota. 



Geographical distribution. — Sciurus cestuans, including its two varie- 



* Button's description of Lc Petit Giui-lhiguct would lead one to suppose it to have been based on an 

 adult individual. He says .... " les testicules de ce petit guerlingnet o"toieiit beaueoup plus gros que 

 ii-ii x dn grand gnerlinguet, a proportion du corps, quoique ces partes present dans le grand guerlingnet 

 de la merae grosseur que dans dos ecureuils." — (Hist. Nat. Siij>i>I. torn, vii, p. 204. ) It seems certain tbat a 

 species of Squirrel no remarkable as Ibis could not so long remain unknown in a region whose zoology 

 is now so well known as that of Cayoune and Eastern Brazil. 



