1906.] Allen, Mammals from Western Mexico. 249 



in August are all adult. These Tepic and Jalisco specimens do not 

 differ appreciably from the large series taken near Escuinapa, Sinaloa. 



21. Reithrodontomys colimae Merriam. 

 Two specimens, immature, Volcan de Fu<=ro, July 5 and 12. 



22. Neotoma sinaloae Allen. 



One specimen, Wakenakili Mountains, an eastern spur of the 

 Sierra Madre, May i, 1905. This specimen is not appreciably different 

 from topotypes of the species from southern Sinaloa. 



23. Microtus phaeus Merriam. 



Seventeen specimens, about one-half fully adult, Volcan de Nieve 

 (alt. 13,000 ft.), Jalisco, Sept. 5-18. 



24. Platygeomys gymnurus (Merriam). 



Fifty-two specimens: Las Canoas, near Zapotlan, Aug. 5-19. 

 About 40 are in the red phase of coloration and 12 in the dusky 

 phase, varying from p'uinbeous more or less suffused with dark 

 chestnut to slaty black. They include all ages from very old to 

 young less than one-fourth grown. 



25. Perognathus flavus mexicanus Merriam 

 Seven specimens, Las Canoas, Aug. 9-22. 



26. Heteromys pictus pictus Thomas. 



Seventeen specimens, collected as follows: Rio Santa Maria, 8 

 specimens, Feb. 1-4; Wakenakili Mountains, 7 specimens, April 27, 

 May i, 8, 10; Sal se Puerdes, i specimen, May 10. These localities 

 are near the Santa Maria River, in the high tableland and eastern 

 spurs of the Sierra Espirito de Santos, at an elevation of about 7000 

 feet. Also i specimen from Estancia, Feb. 28, and 2 from Arroyo de 

 Plantanar, Feb. 18 and 20. 



In size, color, and all external characters these specimens are not 

 distinguishable from either true pictus or the form named plantinarensis 

 by Dr. Merriam. The nasals, however, are truncate posteriorly, 

 as in pictus, and not emarginate, as in plantinarensis and escuinapcs. 

 Plantinarensis is apparently a southeastward extension of the southern 

 Sinaloa form I have named escuinapce, with which it agrees in the 

 form of the nasals, but it is smaller and brighter colored. 



