414 i [OcTOBER, 
Very much resembles the common mouse. Burrows in the earth and comes 
out at night to eat. Its food appears to consist chiefly of green vegetables. 
In the preliminary remarks to this memoir, I alluded to a species of Mus in- 
habiting the Southern States, which might be considered as native and not im- 
ported, which was mentioned in Audubon and Bachman’s Quadrupeds as a variety 
of Mus rattus. This animal was known many years ago to Seba, Klein and 
Brisson, and figured or described by them. The following description of it 
made many years ago, although some what imperfect, may help to point it out. 
Mus Americanvus. Hair dark cinereous, above tipped with reddish brown, 
and dusky with many long scattering hairs of the latter color, beneath with 
white, having a tinge of yellow particularly towards the sides. Ears rather 
large, oval, blunt, naked. Feet whitish, covered with short hairs. Thumb tu- 
berele furnished witha short blunt nail. ‘Tail terete, long, annulosely scaly, 
furnished with short hair. | 
Hab. In Georgia and Carolina. Mus Americanus Turton?s Linneus, Vol. I. 
p. 950. Rattus Americanus Brisson, Regne Animale, p. 172. Mus Americanus 
Klein, Quad. p. 53. Seba, Vol. II. tab. 29, fig. 2. 
This rat was formerly very common in the midland counties of Georgia. I, 
however, know nothing of its habits. The following measurements were taken 
from many different specimens. Length of head and body 7.74; tail 7.8; head 
2.05; ears .9. 
Mus Viretnianus. Color entirely white. Ears, feet and tail flesh color. 
Eyes brown. Ears moderate, blunt, naked. Feet thinly covered with short 
hair; thumb-tubercle with a short blunt nail. Tail thick, rather blunt, quad- 
rangular, the upper side convex, the others plane, annulosely scaley, with short 
hairs proceeding from the base of the rings. 
Hab. In Texas. 
Length h. and b. 7.3; tail 6.2; diameter at root .3, at point .2. 
Mus Virginianus Turton, |. c., p. 82. Mus albus virginianus Brisson, |. ¢c., 
p- 173. M. agrestis virginianus Klein, 1. ¢., p. 57. Seba, Vol. I., tab. 49, fig. 4. 
Virginian rat Pennant. Art. Zool., Vol. I., p. 32 
In the year 1840, a ship arrived at New York, from Tampico, which was over- 
run with rats of this species ; a number of them were given to Mr. J. J. Audubon, 
who made a drawing of the animal and kindly gave me one, from which the 
above description was made; it is not as full and perfect as it might be, as [ had 
no thought at the time of ever publishing it. The cranium differed in many respects 
from that of the M. decumanus, to which it appeared evidently allied, although 
the tail was so different. I shall close these observations with a few remarks 
on some other Rodentia. 
Neoroma FLorIpANUM. Is by no means confined to the southern states, three 
individuals having been taken by Mr. Bell, of New York, near Nyack, on the 
western bank of the Hudson river, about twenty miles above the city. One of 
these was considerably larger than any I had ever seen, the head and body mea- 
sured 11 inches, the tail 7. 5. 
This animal was first described by Mr. Ord, in the Bulletin of the Société 
Philomathique de Paris, in the year 1818, under ‘the name of Mus floridanus, and 
afterwards in the Journal of the Academy of Natural Sciences, of this city, as 
Neotoma floridana. Harlan arranged it under the genus Arvicola, from which it 
differs very much in its dentition, as wellas in other respects. It is the Ameri- 
ean rat of Pennant, Arct. Zool., vol. i., p- 13 where he confounds it with a 
Siberian animal described by Pallas. 
Sremopon uispipus. This animal is subject to considerable variation in the 
middle molar of both jaws, which has usually but one external and one internal 
enamel fold on each side, sometimes, however, there are two external folds, the 
additional one being anterior and smaller. 
' Weare indebted to Mr. Ord for the first published notice of this rat, which 
