Descriptions of Six New Ground Squirrels. 71 



of belly; feet soiled whitish; tail grayer and lsss fulvous than in mollis. 

 Young similar to young of mollis, but decidedly darker ; head and neck 

 pale dull-fulvous instead of buffy-ochraceous ; tail strikingly shorter and 

 darker. 



Cranial characters. — Skull similar to that of mollis, but shorter and rela- 

 tively broader; rostrum conspicuously shorter ; molariform teeth smaller 

 (tooth row 1 mm. shorter) ; nasals shorter but variable, usually ending 

 behind plane of premaxiltee. 



Measurements. — Type specimen : Total length 198 ; tail vertebrae 38 ; hind 

 foot 30. Average of 3 specimens from type locality : Total length 194.3 ; 

 tail vertebrae 40 ; hind foot 30.3. 



Spermophilus tridecemlineatus alleni* subsp. nov. 



T;/pe from Bighorn Mts., Wyoming. No. 56050, J\ U. S. Nat. Mus., 

 Biological Survey Coll., Sept. 18, 1893. Collected by Vernon Bailey. 

 Original No. 4383. 



Characters. — Size small (nearly as small as parvus) ; ground color of 

 upper parts fully as dark as in typical tridecemlineatus ; li^'ht spots in 

 dorsal rows relatively larger and tail darker and much less reddish than 

 in tridecemlineatus. 



Cranial characters. — Skull and teeth similar to those of parvus (perhaps 

 very slightly larger), but audital bullae very much smaller. 



Measurements. —Type specimen: Total length 211; tail vertebrae 74 ; 

 hind foot 32. 



Spermophilus tridecemlineatus texensis subsp. nov. 



Type from Gainesville, Cooke Co., Texas. No. IHf> c? a d., Merriam 

 collection, April 15, 1SS6. Collected by G. H. Ragsdale. 



Characters. — Similar to S. tridecemlineatus, but smaller; ground color of 

 upper parts, including base of tail, redder ; middle stripe of under side of 

 tail uniform deep reddish, not grizzled with black ; no yellowish-olive 

 tinge in any pelage and less seasonal difference in color than in any of 

 the other forms. 



Color. — Winter pelage : Ground color of upper parts, including base of 

 tail, rich deep ferruginous or rusty, slightly grizzled with black hairs ; 

 nose grayish, slightly grizzled with rusty; sides of neck, feet, and under 

 parts buffy ; head marblings, dorsal stripes and spots, chin and lips 

 huffy-white ; rusty under side of tail sometimes partly hidden by buffy 

 tips. Summer pelage : Similar to winter pelage, but ground color duller 

 and light stripes and spots more buffy. 



* In honor of Dr. J. A. Allen, who first defined and named the sub- 

 genus Ictidomys to which the tridecemlineatus group belongs, and to whom 

 we are indebted for its two best marked members —pallidus and parvus. 



