758. RELATIONSIIII'S OF TAYLORS MOl'SK TRUE. 



Upon oxiuniiiini;' criticiilly .si>e(',iiiu'iis of tSilomi/.s lnylori^ 1 liiid fliat a 

 diflereiit coinbination of cliaiacters exists. Thus, the anterior upper 

 molar has three (;iisi)S on eaeh side, and the List lower molar is some- 

 what elongated, as in Vesjyerimus, but, on the contrary, the coronoid pro- 

 cess is high and ])roininent, as in (}i>i/chonij/s. The nasals are trunca- 

 ted behind, as in ]'e,spcrl)nns. In the proi)ortion of the length of tlie 

 tail, however, tlie species is intermediate between the two subgenera. 

 Thus, in ())iycJi(>tiii/s the average lengtli of the tail, for all the specimens 

 of the several species cited by Dr. IMerriam in 1SS9 (excei)t 0. loiif/ljx's), 

 is 40 per cent, of the length of the head and body; the longest tail, 02 

 per cent., is f(mn<l in O. Jongicaudus^ and the shoitest, 30 per cent., in O. 

 melanoi)hr\)s. The average for four specimens of Sltomys {V(\s peri nuts) 

 leucopus is 89 per cent., while in aS". tuylori'it is 05 to 70 per cent. 



The hind feet in S. idi/Iorihaveiiix tubercles, as in ordinary Vespcrimns, 

 but some hairs are found on the anterior part of tlie soles as far as the 

 base of the toes, and even under the toes themselves. 



On account of the peculiar combination of characters mentioned 

 above, I am disposed to regard ^S". taylorl as the type of a separate sub- 

 genus, which may be termed B<(i(>mys. 



Baioniys, snli^eii. tiov. 



Ascending ramus of mandible short and erect. Condyle terminal. 

 Coronoid process well developed, uncinate, and near the condyle. 



Size very small, tail short. Plantar tubercles, six. Soles hairy. 



With Vesperimi(.s and OnyehomySj this subgenus will form one section 

 of the genus Sitomys. It is more closely allied to the former than to 

 the latter. In Vcs^xrimus, the nearest ally, as jNlr. Thomas has pointed 

 out, is S. ( Vesperinn(s) michiyfinensis, which has many of the character- 

 istics of aS'. taylori, l)ut so far as regards the skull is typical of the sub- 

 genus to which it belongs. 



