MIIUIIM';— AHVICOr.lN.K-AltVICOI-A UirAlMlS. 



llt.'i 



the sume relntivdy: — Tlin avora^t; liciul and Inxly is to tlir average tail 

 :: 4.35 : 1.50 :: 1 : O.iU ; that !.•», the tail is almost cNactly one-third as Inni; 

 as the head and body. Tlio average fore foot is to the average hind liiot 

 :: 37 : 80; that is, it is a little less than one-half as long. It slionld 1><! 

 observed, likewise, that the variation in the ])roi)ortional lengths of parts is 

 consideral)le, i. e., tiie longe.st Irnnk has not always the longest tail and leet, 

 nor is n long hind foot always accompanied l>y an equally lengthened lore! 

 foot. These caicniations, moreover, it should bo remembered, really exhiitit 

 a minimum of purely individual variation; for the nineteen specimens occurred 

 under the most similar conditions possible. 



We shall next introduce a table of sixteen specimens, all from the same 

 locality, hut taken at different seasons, in dill'erent stages of growth, and 

 ])reparcd by different persons, for which reasons the series may be held to 

 fairly express an average of j)uveh/ itidiridital raiiahiHiy. In color, they an; 

 all so much alike, that no tangible dillerence can be noted, some being merely 

 a shade browner or grayer than others. On an average, they are a triile 

 browner or brighter than the Philcdtlphia series. 



f 



TaBLKXL.— 3/pfl«w»'rt)if»/»o/*fx/(f» fjHcmcnav/A. ujVAV.ivn (olleclfdhy J. W. J', 'h iikti, at MiddUhoro\ .)faHH. 



From this table it appears that the head, from point of the nose to 

 the occiput, averages just one and a third inches in length, which is slightly 

 less than one-third of the head and body together, and a little less than the 

 overage length of tail; its variation is 0.16, or a little over ten per cent, of 



I 11 



