CONTENTS . Introduction ............................................................... History and material .................................................... Distl-ibution ............................................................ External characters ..................................................... Habits.. ................................................................ ornenclature ............................................................... Generic names .......................................................... Specific and subspecific names ........................................... Genus Zapua Coues.. .................. ,. .................................... Iiey to subgenera ....................................................... List of species and subspecies, with type localities ...................... Subgenus Zapua Coues ...................................................... Key to species .......................................................... A7ap eozapua subgenus novum. ............................................... Key to species .......................................................... Eozqua subgenus novum .................................................... ILLUSTR ATION PLATE . Page . PLATE I . SkuIls of Zapas insignia. Z . aelclt. uanua, Z . hzrtlaonius. Z . orarizts. Z . t inotatua a . nd Z . pvitzcepa ..................................... 42 TEXT FI . G URES . FIG . 1 . Molar teeth of Zal ua kudaoniua ....................... . .............. 14 2 . Molar teeth of Zapus insignia ......................................... 33 3 . Molar teeth of Zapus aetchzianua ...................................... 37 4 . Skull of Zapus aetchuanua ............................................ 38 3 No, 15, NORTH AMERICAN FAUNA, August 1899, KEVISION OF THE JUMPING lllICE OF THE GENUS ZAPUS, By E D A A R . D PR EBLE. INTRODUCTION. History and tanterin1.-The Jumping Mice of North America early attracted the attention of naturalists, but their true status and relat, iouships long remairlecl in obscurity. The first reference to any of the species seems to have beeu made by Thomas Pennant, in the latter part of the last century, who mentioned the animal under the name of the Long-legged Mouse of Hudson7s Bay. 1n l780 Zimmermann, bcsiug his description on that of Pennant, and supposing the animal to be congeneric with the jerboas of the Olcl World, named it DQus htidsoniti. Subsequent authors, recognizing the illapplicability of Dipis, referred the species successively to Gerbillus, Jleriones, and Jaculus, until finilly Dr. Elliott Coues, in 1575, after showing that all the generic names previously used were untenable, proposed Zapus. Previous to 1557 a number of specific names mere used for members of this geuus see pp. 10 13, but were applied mainly to speci ne firso m the eastern United States and Canada...