244 Bulletin American Museum of Natural History. [Vol. XXII, 



posterior base. The tail below is sometimes buffy along the median line; 

 and sometimes the back is very faintly suffused with buffy. 



Measurements. Type, 9 ad., total length, 508; head and body, 254; tail 

 vertebrae, 254; hind foot without claws, 60, with claws, 67; ear from notch, 

 3 2 . The collector's measurements of 1 8 specimens ( 1 2 males, 6 females) average : 

 Total length, 528; head and body, 263; tail vertebras, 265; hind foot (without 

 claws), 60; ear from notch, 32. Adult skulls average about 59 in total length, 

 and 34 in zygomatic breadth. 



Represented by 21 specimens, taken as follows: Rancho Palo Amarillo, 

 near Amatlan, Tepic, 4 specimens, Jan. 1-7; Estancia, 5 specimens, Jan. 31, 

 Feb. 2, March 4; Rio Sta. Maria, 3 specimens, Feb. 2, 7; Arroyo de Plantanar, 

 i specimen, Feb. 17; La Cienega, i specimen, April 23; Wakenakili Mountains, 

 6 specimens, April 2$-May 7; La Laja, i specimen, May 28. These localities 

 are all near each other, along the territorial boundary between Tepic and 

 Jalisco, at altitudes ranging from 5000 to 7000 feet. 



These specimens vary from the type described above mainly in 

 the greater or less distinctness of the nape and rump patches, which 

 range from nearly obsolete to strongly developed, in most of the 

 specimens they being well-marked. A few specimens, about one in 

 five, show a slight suffusion of fulvous throughout the dorsal area, 

 only slightly stronger on the nape and rump than elsewhere. These 

 very closely agree with topotypes of 5. p. nemoralis from central 

 Michoacan, and were they all of this character the Jalisco and Tepic 

 series might readily be referred to that form. One or two specimens 

 show a slight infusion of pale yellow in the central line of the under 

 surface of the tail, through the great reduction of the amount of black, 

 which is much less than the amount of white, thus reversing in a 

 marked degree the conditions in cervicalis. Tepicanus also is slightly 

 larger about an inch longer in total length with a relatively 

 longer tail, which slightly exceeds one-half the total length instead of 

 falling slightly below one-half, as in cervicalis. The light colors of 

 te pic anus, as compared with the dark colors of cervicalis, correspond 

 with the semiarid conditions of the enviroment in the case of the 

 former and the markedly more humid environment of the latter. That 

 the difference in color is not seasonal is shown by a series of cervicalis 

 collected in the Sierra de Colima at the same season as the Tepic 

 and Jalisco specimens. 



8. Citellus (Otospermophilus) variegatus variegatus (Erxleben). 



Thirty-six specimens: Arroyo de Gavilan, Jalisco, 3 specimens, 

 Dec. 17, 25; Estancia, Jalisco, 3 specimens, Jan. 28, March 3; Ojo 

 de Agua, Tepic, 5 specimens, Feb. 15; Arroyo de Plantanar, Jalisco, 

 5 specimens, Feb. 17, 18, 20; Rio Ameco, Jalisco, i specimen, March 



