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BULLETIN 56, UNITED STATES NATIONAL MUSEUM. 



REITHRODONTOMYS MEGALOTIS DESERTI Allen. 

 DESERT HARVEST-MOUSE. 



Reithrodonlomys mecialoiis deserti Allen, Bull. Am. Mus. Nat. Hist., VII, p. 127, May 

 21, 1S95 (original description). — Miller and Reiin, Proc. Best. Soc. Nat. Hist., 

 XXX, No. 1, Dec. 27, 1901, p. 98 (Syst. Results Study N. Am. Mam. to close of 

 1900). 



[Reithrodonfomys mcgalofls] j>allidus, Elliot, Field Col. Mus., Zool. Ser., II, 1901, 

 p. 152 (part) (Synop. Mam. N. Am.). 



[Reitliroduntoniys longicaudun] pallidus, Elliot, Field Col. Mus., Zool. Ser., IV, 1904, p. 

 622 (part) (Mam. Mid. Am.). 



TyjM-locality. — Oasis Valley, Nye County, Nevada, 

 Geographical range. — From southern Nevada and Inyo County. Cali- 

 fornia, south to the mouth of the 

 Colorado River, Sonora, and 

 Lower California. 



Description. — Slio^hth^ smaller 

 than E. inegalotis, with a longer 

 tail; color paler; pelage, shorter 

 and harsher. (Fig. 115.) 



Measurements. — Average of 1 

 adult males: Total length, 140 

 mm.; tail vertebra?, 75; hind 

 foot, 18; ear from crown, 11.35. 

 Average of 10 adult females: 

 Total length, 144 mm.; tail ver- 

 tebrffi, 75; hind foot, 17.7; ear 

 from crown, 11.7. 



Retnarli's. — Forty specimens 

 taken along the Colorado River 

 during March, 1894, exhibit but 

 slight individual and age varia- 

 tions. Adults are all pure white 

 below, excepting a few that have 

 clay-colored pectoral patches. 

 They \a,Tj some in the intensity 

 of the yellowish color of the up- 

 per surface. Those that are 

 INCISORS. immature are less yellowish than 



adults, and half-grown young are drab-gray above, grayish white 

 below. A smaller series from Salton and New rivers, on the Colorado 

 Desert, taken during April, closely resemble those from the Colorado, 

 but are a shade paler and more grayish. 



I am indebted to Dr. C. Hart Merriam for the opportunity of exam- 

 ining a large series of topotypes and the type of this subspecies from 

 Oasis Valley, Nye Count}^, Nevada. These differ from those taken 

 by ourselves along the Colorado River, from Yuma to the Gulf of Cali- 

 fornia, and thence westward across the Colorado Desert, in being of a 



b c 



Fig. 115.— REITHRODONTOMYS M. DESERTL 



foot; b, FOREFOOT; c, tail; d, outer 



VIEW OF LOWER MOLARS; C, SAME 



a, HrND- 



LATERAL 

 OF UPPER 



molars; /. CROWNS of upper molars; g. crowns 

 OF lower molars; h, lower incisors; i, upper 



