130 
1876. = Sub-family Jaculinz, Alston, Proc. Zoél. Soc. London, 1876, 89 
(Dipodidex). 
Family Characters—Teeth 18; i. $2}; pm. $2}; m. 3:3. Superior inci- 
sors compressed, sulcate; premolar small; molars rooted. Cervical verte- 
bre unanchylosed (cf. Dipodidx). Cranial portion of the skull shorter 
and broader than in Murdeze. Auditory bulle transverse (cf. Muridex), 
without special development (cf. Dipodid#), Anteorbital foramen large, 
rounded, with a supplementary nick, or additional foramen, at its lower. 
portion. Malar mounting the zygomatic process of the maxillary to 
effect suture with the lachrymal. Zygomatic arch styloid, much de- 
pressed. Trunk enlargéd posteriorly, in correlation with the shortness 
of the forelimbs and great elongation of the hind ones, especially of the 
pes (cf. Muridx, except Gerbillinx) ; nevertheless, the pes with ‘five per- 
fect and separate metatarsals, and five functionally developed digits (cf. 
Dipodidx, Pedetidx). Tail greatly exceeding the trunk in length (cf most 
Muridz), very slender, scant-haired (cf. Dipodide, Pedetidz). Progression 
saltatorial. 
Genus Zapus Coues. 
1825. Meriones, Fr. Cuvier, Dents des Mamm., 1825, 187 (type. Not 
Merwones of Illiger). 
18380. Jaculus, Wagner, Nattirl. Syst. Amphib., 1830, 28 (type. Not of 
Jarocki, 1821, nor of early authors).—Baird, Mamm. N. Am., 
1857, 429.—Alston, Proc. Zodl. Soc. Lond., 1876, 89. 
1875. Zapus, Coues, Bull. U. S.Geol. Survey Terr., 2nd ser., No.-5, 1875, 
255 (type). | 
Generic Characters —Well developed cheek pouches, internal. Digits 
of the hand five, the first rudimentary, with a flat, blunt nail; palms 
naked, granular, and tuberculate. Digits of the foot five, all functional, 
and with perfect claws aad basal webs; sole naked throughout, the heel 
smooth, the rest granular and'tuberculate. Meatus of the ear capacious, 
closed with large antitragal and tragal flaps. Pelage coarse and hispid. 
Size small; configuration modified from an ordinary murine shape; 
physiognomy peculiar. 
ZAPUS HUDSONIUS  Coues. 
LONG-TAILED JUMPING MOUSE. 
1780. Dipus hudsenius, Zinmermann, Geog. ‘Gesch., ii, 1780, 358, No. 268 
(based on the long-legged mouse of Hudson’s Bay, of Pennant).— 
Boddaert, Elench. Anim., i, 1784, 115 (based on Zinmermann).— 
Schreber, “Sdug., 861, No. 6.”—Fischer, Syn. Mamm., 1829, 
040 (otscd-on GZ amcnnacn. 
