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jAIONOOHAPUS op NOKTU AMERICAN KODBNTIA. 





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Tlu! large nmutiiit of inntcrial in this tabic gives tiie fuUdwing results: — 



Tlio average; Iciigtli of the trunk (head and body) is 4.4?, or slightly loss 

 than fonr and a half inches. The minimum, of apparently adult animals, is 

 3.50, the mnxinium is b-lfi, and so two inches and a quarter is the gross 

 anionnt of variation deduced from the figures ns they stand. To maku 

 allowance, however, for probable error, both from inaccuracy of measure- 

 ment and from imperfect preparation uf the dried skins, from which most of 

 the measurements are taken, and thus to keep largely within reasunai>lc 

 bounds, we will add 0.25 to the minimum and sid>tract 0.25 from the maxi- 

 mum. With this very liberal allowance, it will be seen that we have proven 

 a net variation of one and three-quarters inches to occur in the sixty-three 

 specimen^! measured. 



The tail averages 1.59 in this series, with 1.10 and 2.00 as extremes. 

 Making a fai'; allowance for error, as before, its true variation may safely be 

 held at three-quarters of an inch. Its average length relative to the tnnik 

 is as 4.43 to 1.59 :: 1 : 0.36 nearly, or a little over one-third the length of_ 

 the trunk. 



The average hiiul foot is here 0.80, with 0.72 and 0.92 as extremes. 

 Proiiably little or no allowance is here to be made for error, as the feet arc 

 never skinned, shrink but little in^drying, and can be measured to a nicety. 

 'I'he hind foot, then, varies two tenths of an inch in length. 



Wc tabulate a resume of the four preceding series, as far as the three 

 principal measurements, of head and body, tail vertcbrBf, and hind foot, arc 

 concerned. 



Combining the results of the 114 specimens, wc have on average length 

 of trunk of exactly four and one-third inches; a length of tail of 1.69, or alinust 



