412 ) [OcroBER, 
prominent, the head larger, and the fore feet not being so different in length from 
the hind as to cause its usual mode of progression to be by leaps. The propor- 
tion between the fore and hind feet in this species being as 1 to 1°75, whereas 
in H. leucopus it is as 1 to 2. 
3. Hesp. LEucopus. Supra lete badius interdum prope aurantiacus, subtus 
niveus, coloribus a se abrupte disjunctis. Capite subobtuso, auribus magnis, 
erectis, ovalibus, subnudis, margine angustissimo sub-albido. 
Hab. In provinciis borealibus. Hesp. leucopus Wagner, Schreber, Suppl. vol. 
iii. ps 528. Musculus leucopus Rafinesque, Am. Month. Mag., vol. ili. p. 444. 
Mus leucopus Richardson, l. c. p. 142. Id. Dekay, Zoolog. New York, vol. i. 
p- 82. Id. Schinz., vol. il. p. 176. Mus agrarius, var. 2, Turton’s Linnezus, 
vol. i. p. Id. Godman’s Fauna, vol. ii. p. 88. Mus sylvaticus Harlan, Fauna, 
p- 149. (Description translated from Demarest and not applicable.) Arvicola 
Emmonsii Emmons, Mass. Report. p. 61. Cricetus myoides Gapper, Zool. Jour., 
vol. v. p. 204. Cricetomys myoides Schinz., l. c. p. 204. Field Mouse, Pen- 
nant, Arc. Zool., vol. i. p. 131. Vulg. Jumping Mouse. 
Hair dark plumbeous, above tipt with tawny or dark orange, on the top of the 
head and back with brown and tawny, beneath, for at least two-thirds of the 
length of the hair with snowy white; the tawny color of the sides very bright, 
and abruptly separated from the snowy color of the belly, the line of separation 
very distinct and well defined, and curved upward on the sides both before and 
behind the forelegs. Head moderately blunt ; eyes prominent, black and very 
lively ; nose and lips white ; cheeks bright tawny; ears large, erect, oval, blunt, 
nearly naked, being furnished with short, closely appressed hairs, not in very 
great quantity, and narrowly margined with whitish. Fore legs generally white on 
all sides ; hind legs outwardly tawny, inwardly white ; feet pale flesh color, with 
closely appressed white hairs projecting beyond the nails. Tail above brownish 
dusky, beneath cinereous brown. In winter the fur frequently becomes darker 
colored, being over almost all the upper parts dark cinereous mixed with tawny. 
Length in. 3:9; head 1°2;-ears height 55, width +35 ; fore leg -9 ; hind leg -18; 
tail 2:9; tibia and tarsus 1°8. 
Specimens are brought from California and from Oregon that are above much 
darker colored; the plumbeous color of the lower portion of the hair appearing 
more distinctly among the tawny tips, which are thus rendered but here and 
there visible; the upper color is separated from that of the belly as distinctly as 
in others; the outer side of the fore legs, however, is not white, but of the color 
of the back. In other specimens, the upper parts are more uniformly brownish 
tawny, and the belly not so white; the fore legs also are of a dull white. In 
none of them are the white parts so beautifully snowy. All of them that I have 
seen had been preserved in alcohol, and were, therefore, more or less unfit for 
description. There may be really distinct species among them. 
This animal burrows in the ground, forming long galleries, and proves very 
destructive in gardens. It becomes, in some places, impossible to cultivate 
certain species of bulbous roots, as hyacinths, tulips,&c.,without some contrivance 
by which they may be protected from their depredations. The best method’ 
which I have seen used was, surrounding each root witha flower pot, the bottom 
of which was knocked out. The robber does not penetrate very deep into the 
earth, he is thus quickly stopped in his progress, and forced to look elsewhere 
for food. Their usual mode of progression when on the surface is by leaping, 
hence their name of Jumping Mouse. The name of Deer Mouse is given in Ca- 
nada to the two species of Jaculus; it is only used in that country, as the Jaculi 
are so seldom seen in the United States as to be only known to naturalists. In 
the winter they enter houses, particularly cellars, and support themselves in the 
same manner as the Mus musculus. In green houses they are extremely de- 
structive to cacti and other succulent plants. I have never known them to form 
their nests in trees, or to occupy deserted birds’ nests; it is another species of 
this genus which has this habit. This species I have found it impossible to obtain, 
although formerly quite numerous in the vicinity of New York. M. de Selys 
Longehamps, in his Micro-mammalogia, pp. 66 and 67, makes some observations 
