Oryzomys couesi regillus Goldman
Tropical Rice Rat; Spanish, Rata Arrocera Tropical; Tarascan word for rat is Jeyáquihuiri (Hayakewire), or Sarisi
Oryzomys couesi regillus Goldman, Proc. Biol. Soc. Washington, 28:129, June 29, 1915, type from Los Reyes, Michoacán; Goldman, N. Amer. Fauna, 43:37, September 23, 1918.
Range.—Plateau region of Northeast Michoacán.
Specimens examined, 22: nos. 100601-100622, distributed by localities as follows: 1 mi. N Zamora, 5,450 ft., 2; 4 mi. W Zamora, 5,450 ft., 1; 4 mi. S Pátzcuaro, 7,800 ft., 1; 1 mi. E and 6 mi. S Tacámbaro, 4,000 ft., 18.
Remarks.—The tooth-row is longest in the specimens from Zamora, shortest in those from Tacámbaro and intermediate in length in the one specimen from Pátzcuaro. The shorter tooth-row at the lower elevation (Tacámbaro), we interpret as intergradation with Oryzomys couesi mexicanus. In color the specimens from Tacámbaro are, to us, indistinguishable from those from Zamora and Pátzcuaro but the color is notably darker than that of specimens from the vicinity of Apatzingan which are here referred to the subspecies Oryzomys couesi mexicanus. The largest male, fully adult from Zamora weighs 82.9 grams and the largest one from the vicinity of Tacámbaro weighs 73.6 grams.
Oryzomys couesi mexicanus Allen
Tropical Rice Rat; Spanish, Rata Arrocera Tropical
Oryzomys mexicanus Allen, Bull. Amer. Mus. Nat. Hist., 9:52, March 15, 1897, type from Hacienda San Marcos, 3,500 ft., Tonila, Jalisco.
Oryzomys couesi mexicanus, Goldman, N. Amer. Fauna, 43:33, September 23, 1918.
Range.—Semitropical and tropical western part of the state.
Specimens examined, 14: nos. 52018-52023, 52063-52070, from 1,040 ft., 10 kms., W Apatzingan.