_Specimens examined_, 41: nos. 100366-100406; distributed by localities as follows: 1-3/4 mi. S Tacámbaro, 5,700 ft., 1; 1 mi. E and 2-1/2 mi. S Tacámbaro, 4,700 ft., 11; 4 mi. S and 1 mi. E Tacámbaro, 10; 1 mi. E and 5 mi. S Tacámbaro, 4,000 ft., 1; 6 mi. S Tacámbaro, 4,000 ft., 4; 1 mi. E and 6 mi. S Tacámbaro, 4,000 ft., 14. _Remarks._--Osgood (1909:258) has recorded this subspecies also from La Huacana and La Salada. Three adult males with much worn teeth weigh, in grams, 8.3, 9.3, and 10.8. Weights of three adult, nonpregnant, females are 8.1, 9.4, and 9.7. None of our 13 females was pregnant. =Peromyscus maniculatus labecula= Elliot Deermouse; Spanish, Ratón Cuatralvo _Peromyscus labecula_ Elliot, Field Columb. Mus., zoöl. ser., 3:143, February (March?), 1903, type from Ocotlan, Jalisco. _P[eromyscus]. s[onoriensis]. labecula_, Osgood, Proc. Biol. Soc. Washington, 17:57, March 21, 1904. _Range._--Northwestern part of state. _Specimens examined_, 59: nos. 51402-51406, 52175, 52176, 100407-100447, 100484; and 1366-1368, 1370-1372, 1374-1377, of Bernardo Villa R., distributed by localities as follows: Tancítaro, 7; 11 mi. W Zamora, 5,750 ft., 3; 2 mi. W Pátzcuaro, 7,700 ft., 4; 3-1/2 mi. S Pátzcuaro, 7,800 ft., 2; 4 mi. S Pátzcuaro, 7,800 ft., 3; 5 mi. S Pátzcuaro, 7,800 ft., 24; 9 mi. SE Pátzcuaro, 8,000 ft., 6; 1-1/2 km. N San Juan, 2,250 M., 3; 1 km. NNE San Juan, 2,250 M., 7. _Remarks._--The zygomatic arches are less widely flaring in specimens from Tancítaro than in those from Pátzcuaro. =Peromyscus perfulvus= Osgood Marsh Mouse; Spanish, Ratón Breñero _Peromyscus perfulvus_ Osgood, Jour. Mamm., 26:299, November 14, 1945, type from 10 kilometers west of Apatzingan, 1,040 ft., Michoacán. _Range._--Known only from the semitropical Life-zone in western Michoacán. _Specimens examined_, 5: nos. 100593, 100595, 100597, 100598, and 100600, all from 1 mi. E and 6 mi. S Tacámbaro, 4,000 ft. _Remarks._--J. R. Alcorn took these specimens between fields of sugar cane in tall (5 ft. high) grass growing in a belt 10 feet or so wide along side a stream, which a person could step across. The one adult, no. 100597, was recognized at the time of capture as different from any other species known to us, by reason of the long, unicolored, sparsely-haired tail and nearly clear Cinnamon Rufous color above, white underparts, white feet, and dark brown ears. The four other specimens in darker immature pelage are plumbeous and cinnamon whereas immature individuals of comparable age of _Peromyscus banderanus_ caught in the same place are plumbeous above and lack the cinnamon color. The immature animals of the two species differ in color more than do the adults. Osgood (1945:300) has recorded eleven specimens from the type locality. Our one adult weighs 52.4 grams. =Peromyscus boylii evides= Osgood Brush Mouse; Spanish, Ratón de Chaparral