292 XENOMYS. NEOTOMODON. 



stout; upper molars with three roots, lower with two; the series 

 large, with flat crowns, and with rounded alternating closed triangles; 

 first upper molar with one anterior and one posterior closed loop, and 

 one external and two internal lateral closed triangles; second and 

 third upper molars with one anterior and one posterior closed loop 

 and one lateral closed triangle on each side; last lower molar deeply 

 incised on inner face by a reentrant angle ; on outer side is an anterior 

 and posterior loop and a nearly closed triangle about the middle of 

 the tooth ; supraorbital beads well "developed ; lachrymals and inter- 

 parietal large. 



296. nelsoni (Xenomys), Merr., Proc. Biol. Soc. Wash., vn, 1892, 



p. 161. 

 NELSON'S WOOD RAT. 



Type locality. Hacienda Magdalena, between City of Colima and 

 Manzanillo, State of Colima, Mexico. 



Geogr. Distr. State of Colima, Mexico. 



Genl. Char. Size moderate; tail shorter than head and body. 

 Skull resembling that of Neotoma, but differing in the characters 

 given above. 



Color. Above fulvous, mixed with black on the back; orbital 

 ring dusky; a white spot above the eye and one below root of ear; 

 lips and fore part of cheeks white, rest of face fulvous; under parts 

 creamy white; tail dark umber brown, unicolor; hands and feet 

 whitish. 



Measurements. Total length, 300; tail vertebras, 143; hind foot, 

 30; ear from crown, 18 ; from anterior root, 22. (Ear lengths from dried 

 skin, others taken in the flesh.) Skull: occipito-nasal length, 40.6; 

 Hensel, 33.3; zygomatic width, 32; interorbital constriction, 6; length 

 of nasals, 14; palatal length, 19.3; length of upper tooth row, 8.6. 



57. Neotomodoii. 



Neotomodon Merr., Proc. Biol. Soc. Wash., xn, 1898, p. 127. Type 

 Neotomodon alstoni Merriam. 



Skull broad; braincase short; molars rooted, large, crowns flat; 

 upper first and second molars with three external salient loops and 

 two reentrant angles; and two internal salient loops and one reen- 

 trant angle; third upper molar small, rounded; lower first and second 

 molars with three salient loops and two reentrant angles externally 



