204 PROCEEDINGS OF THE ACADEMY OF [Feb., 



The two color phases appear to run together as several specimens 

 examined are almost intermediate, for while the upper surface will 

 incline toward the brown phase, the lower surface strongly resembles 

 the rufous form. The type, described by Miller, apparently does not 

 represent the extreme of the brown phase. From the specimens 

 examined the brown phase may l^e said to be commoner than the 

 rufous form. 



Skull and Teeth. — Except for the difference in size, the skull and 

 teeth are as in Ch. rubiginosa. 



Measurements. — Average of representative series of fourteen speci- 

 mens: Total length 78.8 (77-85); length of head and body 58.8 

 (56.5-63.5); length of head 23.6 (22..5-24.5) ; length of ear 20.5 (18.5- 

 22.1); length of tragus 5.8 (5-6.4); length of forearm 56.5 (54-59); 

 length of thumb 9.8 (9.1-11); length of third digit 93 (87-97); length 

 of tibia 20.2 (19-22); length of foot 12.9 (12.5-13.5); length of tail 

 21.2 (19.4-23.5). 



Average of eleven skulls: Greatest length 21.2 (20.9-22); greatest 

 zygomatic width 11.8 (11-12.5); interorbital width 4.4 (4.2-4.8); 

 breadth of brain-case above roots of zygomata 10.3 (10.1-10.5); 

 height at base of second premolar 4.8 (4.6-5.1); height of brain-case 

 8 (7.8-8.2); width of palatal constriction 1.6 (1.4-1.8); length of 

 palate from anterior foramina 8.5 (8.3-9.2) ; width of palate including 

 teeth 7.4 (7-7.9); greatest length of mandible 15.8 (15.4-16.5). 



Remarks. — This race can easily be distinguished from true rubiginosa 

 by the difference in size. 



Specimens Examined . — Forty-six specimens; eight skins, thirty-six 

 alcoholic individuals, one odd skull: 



Near Tehuantepec, Oaxaca, Mexico. (Biological Survey.) [L] 



Huiltepec, Oaxaca, Mexico. (Biological Survey.) [1.] 



Ometepec, Guerrero, Mexico. (Biological Survey.) [3.] 



Morelos, Mexico. (U. S. N. M.) [4.] 



Mirador, Vera Cruz, Mexico. (U. S. N. M.) [1.] 



CoHma City, Cohma, Mexico. (Biological Survey.) [2.] 



Hacienda Magdalena, Colima, Mexico. (Biological Survey.) [5.] 



Ameca, Jalisco, Mexico. (Biological Survey.) [5.] 



Bolahos, Jalisco, Mexico. (Biological Survey.) [4.] 



South shore of Lake Chapala, Michoacan, Mexico. (A. M. N. H.) 



[4.] 



San Bias, Tepic, Mexico. (Biological Survey.) [11.] 

 Chacala, Durango, Mexico. (Biological Survey.) [5.] 



