1914.] 



EEITHEODONTOMYS FULVESCENS GROUP. 



53 



gap between the ranges of these two forms^ but further collecting in 

 ^lichoacan and Guerrero may show that they intergrade. From 

 toltecus this form differs, as already pointed out, in haTing a decidedly 

 smaller skull, larger ears, and whiter belly. A specimen from Hua- 

 juapam, Oaxaca, is intermediate in characters between the two forms. 



Specimens examined. — Total number, 22, from the following locali- 

 ties in Mexico : 



Oaxaca: Huajuapam, 1; Oaxaca, IS; Yalalag, 1. 

 Guerrero: Tlalixtaquilla, 1; Tlapa, 1. 



REITHRODONTOMYS FULYESCENS CHIAPEXSIS subsp. nov. 



Chiapas Harvest Mouse. 



Type from Canjob, Chiapas, Mexico. No. 132865, U. S. Nat. Mus., 

 Biological Survey Collection, adult. May 2, 1904; Nelson and 

 Goldman. Origmal No. 16741. 



Distrihution. — ^Highlands of Chiapas. 



Characters. — Similar to Jielvolus but darker and smaller, with smaller 

 ears. 



Color. — Upperparts ochraceous-salmon heavily lined on back with 

 black hairs; lateral line of sahnon moderately well defined; ears fus- 

 cous; underparts grayish white; tail fuscous above, soiled whitish 

 below; feet grayish; ankles fuscous. 



SlcuU. — ^Not appreciably different from that of Jielvolus. 



Measurements. — ^Average of 8 adults from type locahty: Total 

 length, 169 (163-183); tail vertebrae, 96 (92-102); hmd foot, 20.1 

 (20-20.5); ear, 14. Skull: (See table, p. 81). 



RemarTcs. — This is a small dark form apparently most nearly related 

 to Jielvolus. In size and general color it resembles tenuis rather closely, 

 but is darker, especially on the head and ears. It is ahnost as dark above 

 as difficilis, but has whiter underparts. It closely resembles aurantius 

 also, but the underparts are more nearly pure white (never tinged with 

 buff), and the general tone of the upperparts is sHghtly paler. The 

 skull of cJiiapensis averages a httle broader with flatter braincase and 

 shorter nasals than that of aurantius. 



Specimens examined. — Total number, 17, from the following locah- 

 ties in Mexico : 



Chiapas: Canjob, 9; Comitan, 4; San Bartolome, 3; San Yicente, 1. 

 REITHRODONTOMYS FULVESCENS NELSONI subsp. nov. 

 Nelson Harvest Mouse. 



Type from Colima, Colima, Mexico. No. fUff; U. S. Nat. Mus., 

 Biological Survey Collection, ? adult, Mar. 9, 1892; E. W. Nelson. 

 Origmal No. 2050. 



Distrihution. — Coast region of CoHma (and Jalisco?). 



