

i < 



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II 



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80 



MONOOUArilH OF NOUTfl AMKUICAN llODKNTIA. 



under 2.00 ; most lails range between 2.00 nnil 2.50, nn<l not n tail touches 

 3.00, wliidi last is an onlinar)' lengtli of tail for true leucopm. The feet give 

 no (lata (ranj,nng from 0.05 to 0.77, with an nveragc of about 0.77), ncitlicr do 

 the ears. The siiorter tail, on an average, is the sole datum as far us form is 

 cnnccrni'tl. 



Close scrutiny of the table, however, shows that a considerable part of 

 the series has the tail equally or even exceeding the average of leucopua. 

 Secondly, this feature does not obtain in all tlic specimens from any given 

 locality; thus. No. 1032, with the shortest tail in the lot, is associated in 

 Kan.sas with veritable leucopm; Nebraskan examples range from 1.76 to 2.75 

 in length of tail; Utah ones from 1.80 to 2.30; Fort Crook ones about the 

 same; New Mexican and Sonoran ones from 1.93 to 2.65.* In short, we find 

 in almost every locality a greater difference in the several tails than that dis- 

 tinguishing thorn collectively from leucopm; and we can only say that 

 they average half an inch less than the average of leucopus, about equaling 

 the trunk alone instead of about equaling the trunk plus three-quarters of the 

 head. " ' "' - 



As this tinishes what we have to say of the form of these western 



United States mice, we here insert our table, and then take up some other 

 points. 



Tablk Wii.—!dtamrementt of eiijhly-otie (and IM of other) iptcimm <tf n^ppoud llKSfKKOtlYB iJivCOTVB 

 Hu.NUUlENSis Jrom Ike Middle Htgion, Vnilcd Slata. 



[S. B.— Many uf tbfM n|MH;inu>nR arc not fairly diatincitlahablo tnm ordinary leveoput.\ 



* TlieM neem to be Ifueopu*. 



' Reully from 1.93 to S.UOI For No. 145, collected by Mr. Clark ou the Mexican Bonndary, Bhowed 

 a tall of 3.05, and no bad to be turned over to " texanns". 



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