MUinJ)Ai:~81(;MOI)()NTES— UESI'EKOMYS LEUCOPUS. 



59 



Tlic average leiigtli of tlie trunk (liend an<l ImkIj) of lliis series is a little 

 over tliree and a quarter incites. 



The average length of the tail-verteboc is almost exactly three inches. 

 As the usual length ol" the terminal pencil of hairs is about two-tenths of an 

 inch, the tail may he considered as averaging a little less than the length of the 

 trunk. 



The distance from nose to eye averages barely over half an inch ; tiiat 

 from nose to ear, barely over nine-tenths of an inch ; the length of tlie head, 

 about one inch and an eighth. 



The jialms, with the nails, are barely over one-third of an inch. 



The soles, with the nails, are almost exactly Ibur-fiflhs of an inch. 



The ears average half an inch and hall" a tenth of an inch in lieight, 

 measured from the notch in front. 



With these standard dimensions, we have the tbllowing range of vari- 

 ation : — 



Of the ears, 0.50 to 0.C5 — a difTerence of 0.15. But these wide extremes 

 are not often exhibited ; the ordinary variation is within 0.10, or about twenty 

 per cent, of the mean. 



The soles run from 0.70 to 0.83 — a difference of 0.13, and ordinarily range 

 from 0.75 to 0.^0. They do not appear to vary quite as much as some other 

 parts; but this may be partly due to the fact that their admeasurement is made 

 with great accuracy, and that they do not change much in drying. 



The palms range from 0.30 to 0.40 — a difference of 0.10, or nearly thirty- 

 three percent, of the mean. But tiiis is a difficult measurement to nuike 

 with nicety, and probably the real variation is not quite so great. 



The distance from nose to eye ranges (among the alcoholics, alone reli- 

 able in tbis instance) from 0.49 to 0.59 — a difference of 0.10, or twenty per 

 cent, of the mean, as before. The distances from nose to ear, 0.80 to 1.02, 

 and from nose to occiput, 1.02 to 1.25, appear t'ghtly more variable. 



But the most important point is the deter (tion of the total length of 

 trunk and of tail, and of their relationa to eacii othc . for several siippo.sed 

 species are implicated in this matter. As the figures stand, the shortest speci- 

 men has the trunk 2.33 "inches, and two others 2.50; but these are not lull 

 grown, and it will l)c well to fix the minimum adult length at not le-ss than 

 2.75. The maximum length as given is 4.00, but the two or three specimens 

 which alone txjuch this figure are certainly overstuffed,* and it will be safe Ut fix 



* Wo bUTo leen tpecimeiis »' Seil up to 4.50 without' obvious diotortion. 



