46 SPERMOPHILES OF THE MISSISSIPPI VALLEY. 



Table showing contents of cheek pouches of 11 Striped Prairie Spermophiles 

 {Spermophilus tridecemlineatus). 



Sex. 



Date. 



Locality. 



Percent- 

 age of 

 animal 

 matter. 



Percent - 



ace of 

 vegetable 

 matter. 



Contents. 



1887. 

 May 27 



May 30 

 June 14 

 June 18 

 Sept. 6 



1888. 

 July 3 



1890. 

 Oct. — 



Browns Valley, Minn 



do 



Harwood, N. Dak 



Grand Forks. N. Dak 

 Fort Buford, N.Dak. 



Buffalo Gap, S. Dak. 

 Fort Snelling, Minn 



.do 



1889. 

 May 19 



1892. 

 Aug. 23 



Aug. 31 



Graham County, Kans 



Washburn, Tex 



Kiowa, Kans 



100 



100 

 100 

 100 

 100 



100 



100 



100 



100 

 100 

 100 



43 grains of wheat; 400 seeds of 

 millet; 2 seeds of Stipa spartea,- 

 1 seed of Polygonum. 



Seeds of Lithoftpermum. 



71 grains of oats. 



31 grains of oats. 



127 seeds of Helianthus. 



Seeds of a Stipa. 



1,388 seeds of bindweed; 30 sesds 

 of pigeon grass; 4 seeds of panic- 

 grass (coll. by Dr. E. A. Mearns) . 



1,075 seeds of ragweed; 95 seeds 

 of bindweed; 110 seeds of panic- 

 grass (coll. by Dr. 1 *:. A.Mearns). 



163 seeds of black locust. 



Seeds of prickly pear (Opuntia 



r. cymochila). 

 Wild peas (Hogackia purthiana). 



MEXICAN SPERMOPHILE. 



Spermophilus mexicanus (Licht.). 

 [Map 3, B.] 



Description. — This species resembles Spermophilus tridecemlineatus. The ears pro- 

 ject but slightly from head, and the tail is long and quite bushy. The sides and 

 legs are buff; the belly and throat whitish; the back light brown with usually 

 nine or eleven rows of white or buff spots, no solid buff stripes, but the spots are ar- 

 ranged in rows extending from head to tail along middle of back and become shorter 

 laterally; the dorsal stripe is indistinct.* 



The following measurements are those of an average-sized specimen selected from 

 twelve adults: Total length from nose to tip of tail vertebrcne, 308 millimeters (12£ 

 inches) ; length of tail vertebrae, 128 millimeters (5 inches) ; length of hind foot from 

 point of heel to point of longest claw, 42 millimeters (If inches). 



Range. — This Mexican species enters the United States only in south- 

 western Texas and southern New Mexico, extending thence over the 

 table-land of Mexico to Zapotlan, Jalisco, and as far south as the Valley 

 of Mexico and Orizaba. 



The area shown on the map gives an idea of only about half of its dis- 

 tribution. Itis known to occur in at least nine states of Mexico — Coahu- 

 ila, Guadalajara, Guanajuato, Hidalgo, Mexico, Nuevo Leon, Puebla, Ta- 

 maulipas, and Vera Cruz. Its range apparently extends across the table- 

 land of Mexico from Mt. Orizaba nearly to the volcano of Oolima, and 

 from the Valley of Mexico to the mouth of the Rio Grande, and thence 

 northwestward to El Paso. As yet only a few outlying points have 

 been determined and much data is needed to determine accurately the 



*This spermophile is distinguished from the two species of United States spermo- 

 philes, which it most nearly resembles and with whichit comes in contact, as follows: 

 f'rom S. tridecemlineatus by the absence of solid lines of buff alternating with the 

 rows of spots, and from S. spilosoma by the spots being arranged in rows instead of 

 scattered irregularly over the back. 



