1914.] 



SUBGENUS EEITHRODONTOMYS. 



19 



Subgenus REITHRODONTOMYS GigUoU. 



Subgeneric characters. — Enamel pattern of upper molars simple, 

 the first and second each with two outer reentrant angles, usually 

 without accessory tubercles.^ 



BEITHRODONTOMYS HTJMULIS GROUP. 



REITHRODONTOMYS HUMULIS HUMULIS (Bachman). 

 Eastern Harvest Mouse. 

 (PI. I, fig. 1; PI. IV, fig. 1.) 

 Mils humulis Aud. & Bach., Proc. Acad. Nat. Sci. Phila., I, 1841, pp. 97-98. 

 Mus lecontii Aud. & Bach., Journ. Acad. Nat. Sci. Phila., VIII, 1842, p. 307 (Georgia, 



taken by Major John Le Conte). 

 Mus humilis Aud. & Bach., Quad. N. Am., II, 1851, pp. 103-106, Plate LXV. 

 Reithrodon lecontei Le Conte, Proc. Acad. Nat. Sci. Phila., VI, 1853, p. 413. 

 Reithrodon humilis Baird, Mamm. N. Am., 1857, p. 448. 

 Ochetodon humilis Coues, Proc. Acad. Nat. Sci. Phila., 1874, p. 185 [part]. 

 Reithrodontomys humilis Rhoads, Proc. Acad. Nat. Sci. Phila., 1894, p. 161. 

 Reithrodontomys lecontii Allen, Bull. Am. Mus. Nat. Hist., VII, 1895, p. 116. 

 Reithrodontomys humilis dichinsoni Rhoads, Amer. Nat., XXIX, 1895, p. 590 (Willow 

 Oak, Florida). 



Reithrodontomys humilis Rhoads and Young, Proc. Acad. Nat. Sci. Phila., 1897, p. 309. 

 Reithrodontomys humulis Osgood, Proc. Biol. Soc. Wash., XX, 1907, pp. 49-50 (name 

 formally reinstated). 



Type locality. — Charleston, S. C. 



Distribution. — Southeastern United States, east of the Alleghenies, 

 from southern Virginia to central Florida. 



Characters. — Size small; color dark brown; skull narrow, with 

 highly arched cranium and heavy rostrum. 



Color. — General tone of upperparts about Front's brown, being a 

 mixture of blackish brown and pinkish cinnamon, usually darkest 

 along median line; underparts ashy, usually with a tinge of light 

 pinkish cinnamon; tail bicolor, fuscous or hair-brown above, grayish 

 white below; ears fuscous or fuscous-black; feet grayish white. 

 Immature specimens are more fuscous above with slight admixture 

 of brown. 



Slcull. — Braincase narrow, highly arched; rostrum short and broad; 

 nasals broad, ending nearly on a line with end of premaxillse; zygo- 

 mata parallel or slightly contracted anteriorly; palatal foramina 

 broadest in the middle, ending posteriorly about on a line with plane 

 of first molars ; bullae rather small and elongated. 



Measurements. — Average of 5 adults from Georgia and South Caro- 

 hna: Total length, 120 (114-124); tail vertebrae, 57 (53-60); hind 

 foot, 16 (15-17); ear, 9.5 (9-10). Average of 8 adults from Dismal 

 Swamp, Va.: 122; 56; 16; (ear) 9.6. Skull: (See table, p. 81). 



RemarTcs. — This little species — the first member of the genus to be 

 described — ^has a rather extensive range in the South Atlantic States, 

 from southern Virginia to Florida. In Georgia, Alabama, and Florida 



1 Small tubercles irregularly present in some species, particularly B. rufescens and R. dorsalis. 



