SCIUIUDJi— SCIURUS ^ESTCJANS. 757 



Sciurus gilvigulm is Natterer, MS.— Wagner, Wiegm. Arch. f. Naturg. 1813, ii, 43, 1845, i, 148 ; Abband. 



d. K.-B. Akad. d. Wissensch. v, 1850, 279 (from near the mouth of the Rio Madeira, Brazil).— 



Giebel, Siiuget. 1855, 653 (from Wagner). 

 Sciurus guerlingus Castelnau, MS. (= Macroxus leucogaster Gray ; see Gray, 1. c). 

 Macroxus leucogaster Gray, Anu. and Mag. Nat. Hist. 3d ser. xx, 1867, 430. 

 Macroxus flaviventer Castelnau, MS.— Gray, Anu. and Mag. Nat. Hist. 3d ser. xx, 1867, 432. 

 Macroxus kuhlii Gray, Ann. and Mag. Nat. Hist. 3d ser. xx, 1867, 433 (= Sciurus leueoHs Castelnau, MS.) 

 Mgoxus guerlingus Shaw, Gen. Zool. ii, 1801, 171, pi. 156. 

 Brazilian Squirrel, Pennant, Quad. 1771,286. 



Le Grand Guerlinguet, Bufeon, Hist. Nat. Suppl. vii, 1789, 261, pi. lxv. 

 l.c Petit Guerlinguet, Buffon, Hist. Nat. Suppl. vii, 1789, 63, pi. xlvi. 

 Guerlinguet, Shaw, Gen. Zool. ii, 1801, 171. 

 Cochin gclti, Vulgo. 



Var. RUFONIGER. 



Sciurus rufoniger PucnERAN, Rev. de Zool. 1845, 336 (Santa Fe de Bogota^. 

 Sciurus chrgsuros Pucheran, Rev. de Zool. 1845, 337 (Santa F<5 de Bogotii). 



Sciurus cestuans var. hoffmanni Peters, Monatsb. Akad. Wissensch. Berlin, 1863(1864), 654 (Costa Rica). 

 Sciurus hyporrhodiis Gray, Ann. and Mag. Nat. Hist. 3d ser. xx, 1867, 419. 



M,i. roxus irroralm Gray, Ann. and Mag. Nat. Hist. 3d ser. xx, 1867, 431 (" Upper Ucayali, Brazil "). 

 Macroxus griseogena Gray, Ann. and Mag. Nat. Hist. 3d ser. xx, 1867, 429 (Mexico, Honduras, Costa Rica, 

 Panama, Santa F6 do Bogota) ; ib. 4th ser. xi, 1873, 469. 



Var. .ESTUANS. 



Varietal chars. — Length of head and body 7.00 to 8.00 inches; of tail- 

 vertebra a little less (about 6.75 to 7.50); to end of hairs about 9.00 to 9.50. 

 Ears of medium size, rounded ; tail narrow, distichous till near the end, where 

 it is more cylindrical. Pelage soft, short. General color above dark olivaceous - 

 brown, minutely varied with fulvous or pale rufous; below, including inside 

 of the limbs, generally reddish-yellow, varying from pale rufous to yellowish- 

 gray. Sometimes with the yellow restricted to the breast and the middle of 

 the anterior half of the lower surface; or the whole lower surface is whitish, 

 wasbed with fulvous. Above, with the middle of the back, sometimes darker 

 than the rest of the dorsal surface. Tail yellowish-brown, ringed with black 

 (the subterminal black bar very broad), and washed with pale grayish-yellow. 

 The general color of the tail is blackish, washed with pale whitish-yellow. 

 The outer surface of the feet is usually colored like the back. The ears are 

 generally reddish ; the eye is ringed with brownish-yellow. The sides of 

 the muzzle, the chin, and throat are yellowish-white. 



This variety presents no very striking variations in color, and seems to 

 vary but little with locality. I have noticed no tendency to melanism, and no 

 melanistic specimens appear to have been met with by previous authors. 

 The subjoined table of measurements of fifteen specimens, nearly all (thirteen) 

 taken from alcoholic examples, shows only a very moderate range of varia- 

 tion. The specimens are nearly all from Southern Brazil, and are cpiite uni- 



