116 ^leri'idui — Xev SjH'cles of TIkidiohii/s. 



Thomomys limosus sp. hon. 



Type from White Salmon, Gorge of the Columbia. Washington. No. 

 89.724. $ ad.. U. S. National Jrusoum. J^iological Survey Collect inn. 

 June 2(), 181)7. .T. Alden Loring. Original No. 4882. 



Characters — Similar in size and proportions to do ugla si bul color much 

 darker; cranial characters distinctive. 



Color. — Upperparts dark umber brown; underparts dark slate, the tips 

 more or less deejily washed with biiffy or butfy fulvous; feet and tail 

 whitish. 



Cranial characters. — Compuvod with typical dovglasi from Fort A'an- 

 couver, the zygomata are much more broadly bowed outward and less 

 angular, the nasals slightly constricted behind anterior third and some- 

 what expanded and emarginate at posterior end, giving them a 'fish- 

 tail' form: interpterygoid space V-shaped instead of U-shaped: angular 

 process of under jaw decidedly larger and more spreading. 



Measurements. — Type specimen: total length 224: tail vertebne (KS: hind 

 foot 30. Average of 4 adults from type locality: total length 21!>: tail 

 vertebrii- <)8; hind fool 21). 



Thomomys Hesperus sp. nov. 



Ty})e from 'riliamdok. Oregon. No. (5!),82-'>. 9 ii''- ' • ^- NatiiMial 

 Museum, liiological Survey Collcrlion. November !>, ISlll. .1. E. 

 McLellan. Original No. 1181). 



Characters. — Size small: feet very small (hind foot with claws 24); tail 

 short: ears small; color deep rufous. 



Color. — rpper])arts deep rufous; nose, earpatch, and ring round eye 

 dusky: underparts varying from buffy fulvous to salmon fulvous: tail 

 dark above, at least on basal half, whiti.sh below and at ti|) all roiuid: 

 fore and hind feet whitish. 



Cranial ciiarricters — Skull small and light: interparietal large and 

 broadly sub-triangular; bull;e sTuail and rounded, short anteriorly: in- 

 cisors narrow. 



Remarks. — This species dilfcrs so markeilly from its nearest allies that 

 close comi)arison is unnecessary. From T. mrUnvijis Merriam from the 

 Olympic .Mountains, wliich appears to be it.s nearest relative, it dilTers in 

 much smaller size, strikingly smaller feet and .skull: very much nar- 

 rowei' incisors: smaller, shoi-tei', and more rounded bulhi'; smaller and 

 ruirrower basioccipital. much shorter I'ostrum and nasals, shoi'ler tail, 

 and more rufovis coloration. 



Measurements. — Type specimen (9 ad.): total lenj^th kM: tail \erte- 

 bne r)!: hind foot 24. Average of 3 females from lyp<' locality: total 

 length lit): tail \(>rt('br;i' .ll.."): hind foot 24. 



