1906.] Allen, Mammals from Western Mexico. 209 



gray first pelage; nearly all of the others are adult. Three of the 

 specimens are in formalin, the others being skins with skulls. 



10. Peromyscus (Baiomys) musculus musculus (Merriam). 



Nine specimens, Escuinapa, Jan. 5-8, May 27, and July 7 (the 

 latter four specimens in formalin). Not appreciably different from 

 Tepic and Jalisco specimens. 



ii. Sigmodon hispidus colimae Allen. 



Sigmodon hispidus mascotensis BAILEY, Proc. Biol. Soc. Wash. XV, p. 108, 

 June 2, 1902; not Sigmodon mascotensis Allen, 1897. 



Seventy specimens, vicinity of Escuinapa: Dec. 25~Feb. 18, 63 

 specimens; May 26, 27, 2 specimens; July 4-8, 5 specimens. 



About two-thirds of the specimens are old adults, 5 are very 

 young (only a few days old), a few are one-third to two-thirds grown, 

 and the remainder are young adults. The males preponderate, there 

 being 42 males to 26 females. Of the 5 young in first pelage, 4 were 

 taken Jan. 8 and i Feb. 6. 



The 10 largest adult males measure as follows: Total length, 

 299 (267-365); head and body, 156.4 (140-178; tail vertebrae, "136. 7 

 (122-159); hind foot, without claws, 33.4 (32-34); hind foot with 

 claws, about 2.5^4 mm. more, or about 37. The 7 largest females: 

 3 12 (285-337) ',169. 6 (152-184); 136. 7 (122-159); 33. 4 (32-34). About 

 three specimens in each series greatly exceed the others in size, and 

 help to raise the average above the normal. The skulls show these 

 specimens to have been much the oldest as well as the largest speci- 

 mens of the series. 



Mr. Vernon Bailey, in his 'Synopsis of the North American Species 

 of Sigmodon' (Proc. Biol. Soc. Wash., XV, pp. 101-116, June 2. 

 1902), mistakenly adopted the name mascotensis for this species, 

 and renamed my 5. colimce. S. colima, however, is the soft-haired 

 reddish brown species he has named 5. alleni. A reexamination 

 of my original material on which the two species, 5. mascotensis and 

 5. colimcz, were based (4 specimens of each), and topotypes of alleni, 

 shows that all of the present Sinaloa examples represent 5. colimcB, 

 there being no specimens of mascotensis (= alleni Bailey) among 

 them. Mr. Bailey says: "It is this species [alleni] Dr. Allen had in 

 mind in writing his description of mascotensis from which he intended 

 to separate the Colima form, but, as his two specimens of the species 

 here named alleni were not fully adult, he unfortunately selected 

 as his type another specimen that proves to be the same as the form 

 [ June, 1906. ] 14 



