MUKIDiE— SIGMODONTES— SIGMODON II1SPIDUS. 



41 



limits. And, on the other band, Nos. 0996 and 7210 have feet a trifle under 

 an inch, yet are positively identical with No. 9508 for example. And in only /« 

 fifteen Mexican skins the feet range thus: 0.97, 0.98, 1.05, 1.10, 1.10, 1.12, 

 1.14, 1.15, 1.16, 1.19, 1.20, 1.25, 1.30, 1.30, 1.37! 



Mr. Allen has already (I. c. 184) called attention to the fact that Professor 

 Baird's own measurements of <S. "berlandieri" do not bear out his statement 

 that the tail is "equal to or longer than the trunk." "In the latter [S. hispidus], 

 the length of the tail to the length of the trunk is as 69 to 100 ; in the for- 

 mer (S. berlandieri), as 63 to 100 !" Moreover, if the statement were correct, 

 it would conflict with Professor Baird's generic characters ; for he says 

 (p. 501, B. N. A.) that in Sigmcdon the tail is "shorter than the trunk." 



But color has been adduced also, and*we are to inquire about this. No. 

 563, the type of "berlandieri", certainly does not show us the slightest 

 shade of color different from many Carolina skins; the same is the case with 

 some other examples of "berlandieri". Others, however, as Nos. 9021 and 

 8820, are appreciably paler than any Carolina ones we have seen ; being 

 "grayish yellow brown lined with black", exactly as stated by Professor 

 Baird ; and this pallor is even surpassed by Nos. 9384 and 9385. Here the 

 bleached color is striking; indeed, the animals are as whitish as Arvicola 

 "breweri" compared with riparius ; and the tail of one of them (the other's 

 tail is broken off) is longer than usual, though still an inch shorter than the 

 trunk. But these are the specimens with the enormous feet, and so differ 

 from "berlandieri" quite as much as they agree with it ; and they are associated 

 with other specimens quite as dark colored as the ordinary Carolina hispidus. 



Some of Professor Sumichrast's skins are typical of the "Hesperomys 

 toltecus" of De Saussure (7. c), upon which this naturalist based his subgenus 

 Deilemys. There is no question of the accuracy of this identification ; the 

 specimens agree in every particular* with De Saussure's elaborate and faith fid 

 description. When we began to examine the animal, we were inclined to 

 think it different from S. hispidus, viewing the remarkably small feet, which 

 appear the smaller when compared with such feet as those of No. 9384 for 



* Save oue. De Saussure, in commenting upon the affinities of Deilemys, remarks its likeness to 

 Oryzomys, but says the skull lacks the supraorbital "crete" ascribed to Oryzomys by Baird; whereas we 

 find it present in a skull of Sigmodon toltecus, taken from No. 7210. But De Saussnre may have misap- 

 prehended Baird's remarks, or may have had a skull not quite mature. The raised rim of the orbits is 

 not fairly shown except by perfectly adult animals. Moreover, wo find it in many other Mexican 

 species, even in such a delicate oue as Xyetemys sumiehrasti, De Saussure, iu which this author likewise 

 says it does not exist. 



