BCIUItlDJi!— TAMIAB LATRKAMS. 



815 



9820, from Yellowstono Luke (taken in July), is very strongly coltired tiirimgli- 

 out. The whole upper surface nnd sides of the hcnd and neck urn hright 

 reddish-brown, passing into hrownish-ycilow on the tlirunt and brcnst. The 

 light stripe on either side of the back is yellowish-white, the dark ones intense 

 black, and of about the same width as the light stripe by which they are 

 separated. The middle of the back is yellowish-gray ; the sides of the body 

 dull brownifth-yellow ; the lower parts are strongly yellowish, and the tail is 

 edged with the same color. Another 8|)ecimen (No. 2748, Coll. M. C. Z.), 

 from Montgomery, Park County, Colo., is nearly an strongly rufous as the 

 last, but the back of the neck is gray, like the back. The inner black dorsal 

 striiies are obsolete; the outer is short and broad, and dull blackish insteatl 

 of inte.ise block, as in No. 9820. Several others, from the same locality, are 

 very much paler; they show very little brownish on the sides of the nock 

 and head ; the light stripes are well defined and extend from the ears to 

 the hips, but the Idack stripes nre wholly toanting in one specimen (which lias 

 hence exactly the pktura of T. harriii), and in others only the outer arc pres- 

 ent, and nre reduced to n short dusky band. Generally, when the inner black 

 stripe is wanting, the outer is double the width it usually has when both are 

 present. Some specimens show no more rufous on the head than elsewhere, 

 except over a small urea on the forehead. 



In this species, there seems to be very little variation in color with age, 

 and I am unable to correlate any variations with differences of locality. Some 

 of the most diverse examples were obtained at Montgomery, Colo., the seri&s 

 obtained there by myself in 1871 representing nearly the whole range of 

 variation in the whole series. 



Tamias lateralis is the largest species of the genus, and is easily distin- 

 guished by its coloration, especially by the absence of a black dorsal line. 

 With this exception, it has essentially the pattern of coloration seen in T. 

 striaius and T. asiaticus. The white stripes begin at the ears and terminate 

 at the hips, but anterior to the shoulders they arc oflen much obscured by a 

 strong suffusion of rufous. In voice, habits, mode of life, pattern of colora- 

 tion, and external features generally, T. lateralis is a true Tmnias, differing 

 from the other species mainly in the larger size of the first upper premolar. 

 This tooth, however, is still much smaller than in the SpermophiU. The 

 •kull, however, is rather broader and deeper than in the other TamuB. 



This epecies was first described by Say, in 1823, from specimens ob- 



-:t^^ 



