22 PROCEEDINGS OF THE ACADEMY OF [Jan., 



Onychomys arcticeps Rhoads. 



1898. Onychomys arcticeps Rhoads, Proc. Acad. Nat. Sci. Phila., p. 194. May 

 3, 1898. (Clapham, Union county, N. M.) 



A series of eight specimens from the vicinity of Alamogordo, Otero 

 county, N. M., appear to be much closer related to arcticeps than to tor- 

 ridus arenicola Mearns from near El Paso, Tex. The ears are consid- 

 erably blacker than in t. arenicola, and the facial markings are more 

 distinct, while the tail is much shorter. 

 Onychomys ruidosae u. subsp. 



Type: No. 11,091, Coll. Acad. Nat. Sciences of Philadelphia. 9. 

 Ruidoso, Lincoln county, N. M. September 19, 1898. Collected by 

 C. M. Barber. 



Apparently related to 0. melanophri/s. but differing in its more red- 

 dish coloration, darker head and ears, and in the narrower inter- 

 ptery gold fossa. 



Distribution. — Specimens from Hale's Ranch in the Wliite Moun- 

 tain region, have also been examined. 



Color. — Above dull ferruginous, becoming almost clear rufous on 

 the rump ; head and nape blackish-gray washed with ferruginous ; ears 

 blackish-gray beset with fine silvery-white hairs, which are most abun- 

 dant toward the apex; chin pale gra3"ish-pink. Under surface, includ- 

 ing fore and hind limbs (except posterior surface of hind legs), dull 

 white, the under fur plumbeous. Tail rather thinlv haired, with the 

 upper surface mixed brown and white. 



Skull. — The skull of ruidosce closely resembles that of melanophrys, 

 but differs in the broader rostrum and nasals, the more truncate occipi- 

 tal region, the narrower interpterygoid fossa and in the stouter and 

 heavier condylar process of the mandible. 



Measurements. — Flesh dimensions of type: Total length, 156 nun. ; 

 length of tail, 47; length of hind foot, 22. 



Remarks. — While closely related to the melanophrys group, ruidosce is 

 a very distinct species. Relationship exists with fuliginosus Merriam 

 and torridus Coues, but the former is immediately separated by the slen- 

 derer skull and weaker incisors, beside the narrower rostrum and nasals 

 as well as the smaller auditory bulla. From torridus it is easily differ- 

 entiated by the deeper coloration, the grayer head and the more indefi- 

 nite lateral line, as well as the much greater size. 



Peromyscus texanus sonoriensis (LeConte). 



1853. Hesperomys sonoriensis Le Conte. Proc. Acad. Nat. Sci. Pliila., p. 413. 

 (Santa Cruz, Sonora.) 



Three specimens from the vicinity of Alamogordo, Otero county. 



