An Annotated Check List of the Mammals of Michoacan, Mexico Part 8

f. tenuis_. They are lighter-colored (grayer) than either _R. f.

toltecus_ or _R. f. inexspectatus_. The four specimens from Zamora are larger than animals from the vicinity of Tacambaro and average slightly smaller than topotypes of _R. f. inexspectatus_.

By identifying our specimens as _R. f. inexspectatus_ and _R. f.

tenuis_, we are left without any specimens that we, ourselves, have examined, which are referable to the subspecies _R. f. toltecus_. The specimens from Los Reyes which Howell (1914:47) referred to _R. f.

toltecus_ have not been seen by us, and we guess, on the criteria used by us, that the animals would be referable to _R. f. tenuis_. Because Dr. Emmet T. Hooper has a revisionary study of the Mexican _Reithrodontomys_ underway, we have not attempted to bring together all of the pertinent material from different collections as would be required for an ideally thorough a.n.a.lysis of the geographic variation in _Reithrodontomys megalotis_ and _Reithrodontomys fulvescens_.

As ill.u.s.trative of statements made concerning the average size of _Reithrodontomys fulvescens_, the following measurements, all of specimens with much wear on each of the molar teeth, are recorded.

Table headings: A: Number averaged or catalogue No.

B: s.e.x C: Total length D: Length of tail E: Length of hind foot F: Basilar length G: Length of nasals H: Zygomatic breadth I: Mastoid breadth J: Alveolar length of maxillary tooth-row

========================================================================= LOCALITY A B C D E F G H I J ------------------------------------------------------------------------- Vall. Mex. 3 [M][M] 200 114 22.0 17.6 9.3 12.0 10.7 3.7 Patzcuaro 5 [M][M] 170 101 20.6 16.7 8.7 11.6 10.6 3.7 Zamora 100215 [M] 153 82 19.0 15.9 7.8 10.9 10.3 3.5 Zamora 100275 [M] 184 101 21.0 16.5 8.0 11.1 10.4 3.6 Tacambaro 5 [M][M] 159 91 19.4 15.5 8.0 10.5 9.6 3.3 Vall. Mex. 3 [F][F] 184 103 21.0 16.6 8.7 11.4 10.6 3.6 Patzcuaro 5 [F][F] 182 104 21.6 16.8 8.6 11.6 10.5 3.6 Zamora 5 [F][F] 159 91 19.0 16.0 8.4 11.4 10.0 3.5 Tacambaro 5 [F][F] 149 87 18.6 14.9 7.7 10.4 9.5 3.4 ------------------------------------------------------------------------- Note: [M] = Male and [F] = Female.

=Reithrodontomys fulvescens inexspectatus= Elliot

Fulvous Harvest Mouse; Spanish, Raton Moreno

_Rhithrodontomys inexspectatus_ Elliot, Field Columb. Mus.

zool. ser., 3:145, February, 1903, type from Patzcuaro, Michoacan.

_Reithrodontomys fulvescens toltecus_, Howell, N. Amer. Fauna, 36:51, June 5, 1914, part.

_Range_.--Central Michoacan; limits of range unknown.

_Specimens examined_, 15: nos. 100278-100292, distributed by localities as follows: 3 mi. N Patzcuaro, 6,800 ft., 6; 3 mi. NW Patzcuaro, 6,700 ft., 3; 2 mi. W Patzcuaro, 7,600 ft., 2; 2 mi. W Patzcuaro, 7,700 ft., 4.

_Remarks_.--Howell (1914:51) made _R. inexspectatus_ Elliot a synonym of _R. f. toltecus_ and perhaps we should follow him in this. The facts are that in our large series from the vicinity of Patzcuaro, the upper parts are more reddish than in _R. f. toltecus_ from the valley of Mexico, and more reddish than in _R. f. tenuis_ if we correctly interpret Howell's (_op. cit._,:45) description of _R. f. tenuis_. In the color of the underparts the series is, to us, indistinguishable from topotypical _toltecus_ and therefore has more reddish underparts than _R. f. tenuis_, as we know _R. f. tenuis_, from Howell's (_loc.

cit._) description. In size, the series from Patzcuaro is intermediate between _R. f. tenuis_ and _R. f. toltecus_ but nearer the latter.

=Reithrodontomys chrysopsis chrysopsis= Merriam

Volcano Harvest Mouse; Spanish, Raton Dorado

_Reithrodontomys chrysopsis_ Merriam, Proc. Biol. Soc.

Washington, 13:152, June 13, 1900, type from Mount Popocatepetl, Mexico.

_Reithrodontomys chrysopsis chrysopsis_, Howell, N. Amer.

Fauna, 36:66, June 5, 1914.

_Range._--Patamban, 1,200 feet elevation as now known.

_Remarks._--Howell (1914:68) lists nine specimens from Patamban. We have not examined these specimens. He listed at the same time seven of the specimens from Tancitaro, but we have found specimens from Tancitaro to be of another subspecies, _R. c. seclusus_. Accordingly, we are in doubt as to whether the mice from Patamban are subspecies _chrysopsis_, _seclusus_, or an unnamed subspecies and our use here of the name _Reithrodontomys chrysopsis chrysopsis_ for them is, of course, provisional.

=Reithrodontomys chrysopsis seclusus= Hall and Villa

Volcano Harvest Mouse; Spanish, Raton Dorado

_Reithrodontomys chrysopsis seclusus_ Hall and Villa, Proc.

Biol. Soc. Washington, 62: 163, August 23, 1949, type from Mount Tancitaro, 7,800 ft., Michoacan.

_Reithrodontomys chrysopsis chrysopsis_, Howell, N. Amer.

Fauna, 36:66, June 5, 1914, part.

_Range._--Known only from Mount Tancitaro, from 6,000 feet elevation up to at least 11,000 feet.

_Specimens examined_, 22: nos. 51407-51411, 52110-52126, all from Mount Tancitaro, distributed by alt.i.tude as follows: 6,000 ft., 5; 7,800 ft., 10; 10,500 ft., 1; 11,000 ft., 1; no alt.i.tude recorded, 5.

_Remarks._--The 22 specimens in the Chicago Natural History Museum are remarkably uniform in color in spite of differences in age; 17 are so young as to have the first upper molar only slightly worn and 5 are adults. In preparing the original description of _R. c. seclusus_, known only from specimens in the summer pelage, comparison of color was made with only the winter pelage of _R. c. chrysopsis_ and it was pointed out that the differences noted in color between the two subspecies might be seasonal rather than subspecific. A summer specimen of _R. c. chrysopsis_ (K. U. 17980, taken on June 15, 12 km.

ESE Amecameca, 11,500 ft.), is available as the present account is being written. In direct comparison with the original material of _R.

c. seclusus_, all in summer pelage, and in comparison with a specimen of _R. c. chrysopsis_ in winter pelage (January 18), from 30 km. E Amecameca, the summer pelage of no. 17980 is more blackish than the winter pelage and therein more closely resembles that of _R. c.

seclusus_. The same is true of the more spa.r.s.ely haired tail. The ears, however, are blackish as in winter-taken _R. c. chrysopsis_.

This feature and also the large size and different cranial proportions of specimen no. 17980 are in accordance with the differences between _R. c. chrysopsis_ and _R. c. seclusus_ as recorded in the original description of the latter.

=Baiomys taylori a.n.a.logus= (Osgood)

Northern Pygmy Mouse; Spanish, Raton Pigmeo Norteno

_Peromyscus taylori a.n.a.logus_ Osgood, N. Amer. Fauna, 28:256, April 17, 1909, type from Zamora, Michoacan.

_Baiomys taylori a.n.a.logus_, Miller, N. Amer. Land. Mamm., 1911, p. 137, December 31, 1912.

_Range._--Northwestern part of state.

_Specimens examined_, 35: nos. 100331-100365, distributed by localities as follows: 8 mi. N Zamora, 5,500 ft., 2; 11 mi. W Zamora, 5,750 ft., 1; 6-1/2 mi. W Zamora, 5,950 ft., 2; 4 mi. W Zamora, 5,450 ft., 1; 3 mi. NW Patzcuaro, 6,700 ft., 21; 3 mi. N Patzcuaro, 6,800 ft., 5; 2 mi. W Patzcuaro, 6,700 ft., 3.

_Remarks._--Osgood (1909:257) has recorded this subspecies also from Acambaro and Los Reyes. We found that these animals got caught in our traps almost as often in the daytime as at night and concluded that they were less nocturnal, or at any rate more diurnal, than any of the other cricetine mice at the places in Michoacan where we trapped.

=Baiomys musculus musculus= (Merriam)

Tropical Pygmy Mouse; Spanish, Raton Pigmeo Tropical

_Sitomys musculus_ Merriam, Proc. Biol. Soc. Washington, 7:170, September 29, 1892, type from Colima, Colima.

_Peromyscus musculus_, Allen and Chapman, Bull. Amer. Mus.

Nat. Hist., 9:203, June 16, 1897.

_Baiomys musculus_, Mearns, U. S. Nat. Mus. Bull., 56:381, April 13, 1907.

_Range._--Dry, tropical, southwestern parts of state.

_Specimens examined_, 41: nos. 100366-100406; distributed by localities as follows: 1-3/4 mi. S Tacambaro, 5,700 ft., 1; 1 mi. E and 2-1/2 mi. S Tacambaro, 4,700 ft., 11; 4 mi. S and 1 mi. E Tacambaro, 10; 1 mi. E and 5 mi. S Tacambaro, 4,000 ft., 1; 6 mi. S Tacambaro, 4,000 ft., 4; 1 mi. E and 6 mi. S Tacambaro, 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.