412 [October, 



prominent, the head larger, and the fore ieet 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 laete badius interdum prope aurantiacus, subtus 

 niveus, coloribus a se abriipte disjunctis. Capite subobtuso, auribus magnis, 

 erectis, ovalibus, subnudis, margine angustissimo sub-albido. 



Hub. In provinciis borealibus. Hesp. leucopus Wagner, Schreber, Suppl. vol. 

 iii. p. 528. Musculus leucopus Rafinesque, Am. Month. Mag., vol. iii. p. 444. 

 Mus leucopus Richardson, 1. c. p. 142. Id. Dekay, Zoolog. New York, vol. i. 

 p. 82. Id. Schinz., vol. ii. p. 176. Mus agraiius, var. 2, Turton's Linnaeus, 

 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., 1. 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 j 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 Irom 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 with a 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 su)face is by leaping, 

 hence th^nr 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 

 Longchamps, in his Micro-mammalogia, pp. 66 and 67, makes some observations 



