NEW HARVEST MICE 557 



REITHRODONTOMYS DORSALIS sp. nov. 



Type from Calel, Guatemala. No. 77009. $ ad. U. S. National 



Museum, Biological Survey Coll. Jan. 14, 1S96. E. W. Nelson 



and E. A. Goldman. Orig. no. 91 12. 



Characters. — Size rather large ; ears and tail medium ; tail bicolor ; 

 general color grayish above with dusky dorsal area. 



Color. — Upperparts grayish washed with buffy, becoming buffy 

 ochraceous on sides ; top of head and broad dorsal area blackish (from 

 profuse admixture of black tipped hairs) ; underparts buffy whitish, 

 in many specimens suffused with buffy fulvous ; lips and chin whitish ; 

 wrists dusky ; fore and hind feet whitish ; tail dark above, whitish 

 below, with rather sharp line of demarcation. 



Cranial characters. — Skull apparently of the mexicanus type, con- 

 siderably larger iha.n saturatus., but molar teeth small as \x\. saturatus ; 

 rostrum rather long; braincase moderately rounded ; basal length of 

 skull 18.5; zygomatic breadth 1 1.8 ; molar series 3.20. 



Measurements. — Type specimen ( <? ad.): total length 171 mm.; 

 tail vertebrae 92; hind foot 19. 



REITHRODONTOMYS MEGALOTIS ZACATECyE subsp. 



nov. 



73^/^ fi"©"^ Valparaiso Mts., Zacatecas, Mexico. No. 91910. 9 ad. 



U. S. National Museum, Biological Survey Coll. Dec. 6, 1897. E. 



W. Nelson and E. A. Goldman. Orig. no. 11S59. 



Characters. — Similar in general size and proportions to megalotis 

 but much darker and yellower; ears and tail darker, pelage coarser 

 and less fluffy. Upperparts pale dull fulvous brown, becoming buffy 

 ochraceous on sides ; top of head and back conspicuously lined with 

 black hairs; underparts dark (instead of white), washed with buffy 

 salmon ; a pale fulvous pectoral patch. Skull like that of megalotis 

 but braincase somewhat flatter and broader ; nasals ending on plane of 

 premaxillae instead of more anteriorly. 



Remarks. — R. 77i. zacatec(£ resembles subspecies obsctirus from 

 Sierra Madre, Chihuahua, very much more closely than it does typical 

 megalotis. It differs from obscurus in having the upperparts less dark 

 and more yellowish, the sides much deeper buffy ochraceous. 



Measuremetits. — Type specimen (9 ad.): total length 156 mm. ; 

 tail vertebrcB 87 ; hind foot 17.5. Average of 4 specimens from type 

 locality: total length 152; tail vertebrae 83; hind foot 17.5. 



