266 Mr. 0. Thomas on 



Sciurus (Microsciurus) mimulus, sp. n. 



Of the small size and with the cranial and dental cha- 

 racters of the other species of Microsciurus, but with almost 

 precisely the coloration and general appearance of Sciurus 

 medellinensis, Gray (probably a synonym of S. Pucherani, 

 Fitz.). General colour deep brown, profusely grizzled with 

 yellowish fulvous and with a marked black dorsal stripe. 

 Crown and nape indistinctly blackish. Ears finely edged 

 with fulvous ; no whitish postauricular patch. Shoulders 

 grizzled fulvous, with a tinge of rufous. Dorsal line shining 

 black and strongly marked on the middle of the back, fading 

 away anteriorly and posteriorly. Throat and chest rich 

 fulvous, passing on the belly into blackish grizzled olivaceous 

 grey. Limbs like back, the tips of the digits fulvous; inner 

 sides of hips also more fulvous than the belly. Tail-hairs 

 ringed with fulvous and black, their tips dull yellowish. 



Skull narrower and more elongate than in S. ckrusurus, 

 the muzzle especially slender and lengthened. Interparietal 

 very broad transversely. 



Dimensions of the type (an adult female, measured in the 

 flesh by the collector) : — 



Head and body 130 millim. ; tail 109 ; hind foot, without 

 claws, 33 ; ear 16. 



Skull : greatest length 38 ; basilar length 29 ; greatest 

 breadth 23 ; nasals 10*6 x 5 ; interorbital breadth 13"5 ; inter- 

 parietal 4x9; palate length from henselion 15*8; diastema 

 {top. 4 ) 9*5; length of upper tooth-row (excluding^. 3 ) 5'6. 



Hah. Cachavi, N. Ecuador, alt. 167 m. Coll. W. H. F. 

 Rosenberg, Jan. 23, 1897. 



Type B.M. no. 97. 11. 7. 39. Three specimens examined. 

 This little squirrel differs markedly from the other Micro- 

 sciuri — S. (A/.) chrysurus, alfari, and peruanus — by its black 

 dorsal line, the yellow grizzled-brown of its body-colour, and 

 its rich fulvous chest, but has a very striking resemblance to 

 the larger Colombian species of true Sciurus to which Gray 

 applied the name S. medellinensis. The latter, however, is 

 in all probability the same as S. Pucherani, Fitz. (S. ru/o- 

 niger, Puch., nee Gray), of Bogotd, the type of which, as 

 M. de Pousargues has been so kind as to inform me, appears 

 to have only one upper premolar, while its hind foot is 

 39 millim. long without the claws. Its position has been 

 hitherto very doubtful, so that M. de Pousargues's information 

 about it is exceedingly welcome. 



In any case, however, whether S. medel/inensis is or is 

 not a synonym of S. Pucherani, S. (J/.) mimulus has nothing 



