16S Merriam — Descriptions of Nine Neiv Mnmmah. 



Neotoma alleni si>. imv. 



Type No. tl^^U^ ad. U. S. National Musemn (Departim-iit of Agricult- 

 ure collection). From Manzanillo, Colinia, Mexico, January L'(i, 1S92. 

 Collected by E. W. Nelson. (Original number, 179().) 



Measurements (in millimeters, taken in \\qA\ by collector). — 

 Total length, 472 ; tail vertebra^ 225 ; hairs, 4; hind foot, 4B; ear 

 (in dry skin) from anterior root, 29. 



General Characters.— ^\zq much larger than any species hereto- 

 fore described ; ears rather large and sparsely clothed with fine 

 hairs on the posterior surfaces ; tail shorter than the head ancl 

 body, blackish, sparsely haired, the annulations and scales dis- 

 tinctly visible above as well as l)elow ; upper parts deep tawny- 

 red or rusty. 



(Mor. — Upper parts from forehead to Ijase of tail deep fulvous 

 or tawny-ferruginous ; nose and sides of face mouse-gray, tinged 

 with bluish in some specimens ; under surface whitish, the tips 

 of the liair only being white and the })luml:)eous liasal portion 

 showing through ; upper surfoces of feet whitish, more or less 

 clouded with dusky; tail blackish all round. 



Cranial Characters. — Skull largest of the genus. Total length 

 of type, 53 ; basilar length (from inferior lip of foramen magnum 

 to posterior alveolus of incisor), 44; zygomatic breadtli, 27.50; 

 length of upper molar series on alveolus, 1 1 : cranium strongly 

 marked by muscular impressions ; superciliary ridge strongly 

 elevated and continued posteriorly across the outer half of the 

 parietals and interparietal to the occii)ut; interparietal sul)- 

 quadrate with a postero-lateral wing on each side ; ascending 

 ramus of premaxillary short, barely reaching plane of lachr}^- 

 mals, and but slightly exceeding the nasals ; antorbital slit with 

 a tubercle at inferior base; audital bulhe small, connected by a 

 bony process with the hamular processes of the pterygoids ; 

 molar series very large and heavy, al)out one-fourth the basilar 

 length of the skull ; lirst and second upper molars with a lateral 

 closed triangle on each side ; last lower molar shaped like the 

 letter S, '<^^ i" Xenomys, but differing from Xenomj/s in having a 

 shallow reentrant angle on the outer side opposite the deep 

 fold from the inner side ; infracondyloid notch of mandible 

 broadly open and but slightly concave. 



Mr. Nelson writes tliat in the neighborlidod of Manzanillo this 



