REVISION OF THE JUMPING MICE OF THE GENUS ZAPUS. 15 



Skull rather light: brain case narrow; incisive foramina small. 

 Coloration dark and dull. 



Larger; basilar length of skull usually more than 18 imu. 



alascensis. 



Smaller; basilar length of skull usually under 17.5 um\. .teneUus. 

 Coloration not dark and dull. 



Dorsal area very much flecked with color of sides; fall pelage 



with dorsal area nearly black campestris. 



Dorsal area not much flecked with color of sides; fall pelage 



with dorsal area not very dark. 

 Larger; hind foot about 32 mm.; tail usually more than 



140mm ladas. 



Smaller; hind foot usually 30 or 31 mm.; tail usually below 



135 mm hudsonius. 



Size small ; hind foot usually below 30 mm. ; total length of adults usually 

 under 215 mm americanus. 



ZAPUS HUDSONIUS (Zimmermaun). Hudson Bay Jumping Mouse. 



1780. Dipus hudsonius Zimmermann, Geog. Geschichte d. Menschen u. vierfiissigeu 



Thiere, II, p 358. 

 1792. Dipus labradorius Kerr, Animal Kingdom, p. 276 (based on the ' Labradore 



Jerboid Rat of Pennant' ).' 



1798. Dipus canadensis Davies, Trans. Linn. Soc. London, IV, p. 157. 

 1822. GerbiUus canadensis Desmarest, Mammalogie, II, p. 321. 

 1825. Gerbillus labradorius Harlau, Fauna Am., p. 157 (in part). 



1829. Meriones labradorius Richardson, Fauna Boreali-Ainericaiia, I, p. 144. (Not .17". 

 labradorius Dawson, 1856.) 



1830. Jaculus americanus Wagler, Nat. Syst. Amphibien, p. 23. 



1839. Jferiones microccpltalus Harlan, Proc. Zool. Soc. London, 1839, p. 1. 

 1843. Jaculus labradorius Wagner, Suppl. Schreber's Saugthiere, III, p. 294. 



1856. Meriones acadicua Dawson, Edinburgh New Philos. Jouru., new ser., Ill, p. 2. 



1857. Jaculus hndsonius Baird r Mamm. N. Am., p. 430 (in part). 



1875. Zapus hudsonius Coues, Bull. U. S. Geol. Surv. Terr., 2d Ser., No. 5, p. 253; Mon. N. 



Am. Rodentia, p. 467, 1877 (in part), and recent authors (in part). 

 1899. Zapus hudsonius canadensis Batchclder, Proc. New Eng. Zool. Club, I, p. 4. 

 1899. Zapus Jntdsonius hardyi Batchelder, Proc. New Eng. Zool. Club, I, p. 5. (Mount 



Desert Island, Maine.) 



Type locality. Hudson Bay. 



Geographic distribution. As restricted in the present paper, this spe- 

 cies is found from the southern shores of Hudson Bay south to Xew 

 Jersey, and in the mountains to North Carolina, west to Iowa and Mis- 

 souri, and northwest to Alaska. It iutergrades with Z. amerlcanux in 

 the upper part of the Carolinian zone in the Eastern States; with cam- 

 pestris along the edge of the Great Plains, and probably with alascensis 

 somewhere in northern British America. 



General characters. Size medium, smaller than Z. insignia, Z. trinota- 

 tus, or Z. princeps. Skull less massive, with small molars and incisive 

 foramina. 



1 "Inhabits Hudson's Bay and Labradore. This species was sent over from Hud- 

 son's Bay by Mr. Graham." Kerr. 



