_[Sciurus] variegatus_ Erxleben, Syst. Regni, Anim., 1:421, 1777; type locality fixed as Valley of México near the city of México, by Nelson, Science, N. S., 8:898, December 23, 1898. _[Citellus] variegatus_, Elliot, Field Columb. Mus. Pub., zoöl. ser. 4:148, 1904. _Range._--Probably in all semi-arid, rocky habitats of the state. _Specimens examined_, 11: nos. 100128-100135; 51385-51387, distributed by localities as follows: 1 mi. N Zamora, 5,450 ft., 1; 3 mi. NW Pátzcuaro, 6,700 ft., 5; 4 mi. S Pátzcuaro, 7,800 ft., 1; 1-1/2 mi. S Tacámbaro, 5,700 ft., 1; Mount Tancítaro, 1; Pedregal, Tancítaro, 1; Tancítaro, 1. _Remarks._--Rock squirrels were seen along rock fences, around Pátzcuaro, where they are fairly common. On July 17 and 18, 1947, at San Juan Parangaricutiro, one of us (Villa) saw these squirrels running over the newly formed lava bed which was still emitting vapors and which in places (between boulders) was emitting heat detectable by the collectors. This is only additional evidence of the animal's strong predilection for rocks, boulders and cliffs, which has earned for it, in parts of the western United States, the vernacular name "rock squirrel" and in México "_Ardilla de Pedregal_." Howell (1938:138) reported specimens from the following localities: Acámbaro, 1; Los Reyes, 1; Mount Tancítaro, 2; Pátzcuaro, 12; Queréndaro, 1; Zamora, 2. =Citellus adocetus adocetus= Merriam Lesser Tropical Ground Squirrel; Spanish, Cuiniqui; Tarascan, Kuaráki (Kuaraki) _Citellus adocetus_ Merriam, Proc. Biol. Soc. Washington, 16:79, May 29, 1903, type from La Salada, 40 miles south of Uruapan, Michoacán. _Range._--Southern part of state in arid tropical land. _Specimens examined_, 4: nos. 52000, 52001, 51388, 51389, distributed by localities as follows: "Near Tancítaro," 2; Acahuato, 1; Apatzingan, 1,040 ft., 1. _Remarks._--Ground squirrels of this species are fairly abundant in the arid tropical parts of the state. Their burrows are usually found on stony areas along small ravines or under mesquite (_Prosopis juliflora_) thickets. The name cuiniqui in use by the Spanish speaking population is merely a corruption of the Tarascan name. Cuiniqui, therefore, is a particular kind of _ardilla terrícola_ (ground squirrel). =Sciurus poliopus nemoralis= Nelson Michoacán Squirrel; Spanish, Ardilla arborícola; Tarascan, Uakuí (Wakqe) _Sciurus albipes nemoralis_ Nelson, Proc. Biol. Soc, Washington, 12:151, June 3, 1898, type from Pátzcuaro, Michoacán. _Sciurus poliopus nemoralis_ Nelson, Proc. Washington Acad. Sci., 1:50, May 9, 1899. _Range._--Pine and oak forests of most of state. _Specimens examined_, 3: nos. 2102 and 2103 Louisiana State University from 20 mi. E Morelia, 7,300 ft., and no. 1369 B. Villa R. from 1-1/2 km. N San Juan 2,250 meters. _Remarks._--Tree squirrels of this kind have been reported by Nelson (1899:51) from Pátzcuaro and Nahuatzin.