MURIDA—SIGMODONTES—NEOTOMA FERRUGINEA. De 
the hairs white to the roots in the middle, but along the sides with ashy roots, 
somewhat obscuring the purity of the white. Tail nearly as long as the head 
and body together, at least exceeding the body alone, and blackish throughout, 
or so nearly unicolor that the under side is merely a shade paler than the 
upper. Whiskers very long, all jet-black at base, paler at ends. Soles very 
scant-haired back of the posterior tubercle; ears likewise nearly naked (both 
much as in fusc?pes). General form and proportion of parts as in the other 
scaly-tailed Neotomas. Size averaging somewhat less than in Weotoma flori- 
dana (see table of measurements). 
The fine series collected by Professor Sumichrast enables us to charac- 
terize this animal with precision. The five specimens vary but little, the 
difference being mainly in the purity and intensity of the colors; the meta- 
tarsus, however, in one specimen at least (9435), is white, whereas in all the 
others it is clouded with dusky. The animal is related to N. fusczpes in this 
respect, as also in the length and blackness of tail, but is smaller than that 
species, and otherwise distinguished at a glance by its rich rusty-red color, 
by which, furthermore, it is separated from any other of the rat-colored 
United States Neotomas. 
The skull of No. 9507 has no structural peculiarities, but is smaller than 
any adult United States skulls examined; it measures 1.80 in length by 0.95 
across the zygomata. The post-palatal notch may be rather narrow, but is 
not conspicuously so. The dentition affords us nothing diagnostic, as, in fact, 
is the case with all the rest of the genus; and we suspect that any peculiarity 
Mr. Tomes may have noticed in his types of ferruginea will prove only an 
individual feature, to be matched in other species. 
We have not seen the young of this species, and do not know how gray it 
may be in youth; but we should expect that the dark gray or slate color 
of floridana and other northern species would not be perfectly exhibited in 
this case. 
TABLE IV.—Measurements of five specimens of NEOTOMA FERRUGINEA. 
Nose to— 
2/4 
Locality. Collector. = s|&e Remarks. 
. ome, 4 = 2) Ss . 
2 ue So tt = = a b 
Ss & & 
Blalée|a&|/ala|la 
Tehuantepec, Mexico .| F. Sumichrast....| 0.75 | 1.65 | 1.85 | 7.00 | 6.50 | 0.70 | 1.35 | 0.85 | Dry; adult. 
San GO een sesccamecsay see ohecsocdecee 0.80 | 1.60 | 1.75 | 7.00 |.---.. 0.65 | 1.35 | 0.92 | Dry; adult. 
marsha ceotbeeresesed Pee AAR eee Patan Raced beens 7.25 | 7.00 | 0.72 | 1.40 | 0.87 | Dry; adult. 
aati Macaca aereneee peo Seer ccce sored Sasced Cecece Moen 8.00 | 6.75 | 0.68 | 1.30 |.-.--. Dry; adult. 
do afi e Beas | Ree ee Ro 7.75 | 6.75 | 0.75 | 1.45 | 0.90 | Dry; adult. 
