140 



pugnacious, and when given room, moves by sudden springs, holding 

 high its long tail. 



Sub-genus Oeyzomys Baird. 



< Mus sp., Harlan, Am. Journ. Sci., 1837. 



< Hesperomys sp., Wagner, Suppl. Schreb., 1843. 

 X Arvicola sp., Aud. & Bach., Q. N. A., iii, 1853. 

 = Oryzomys, Baird, M. N. A., 1857, 458. 



Sub-generic Characters. — " Superior margin of orbit with a prominen 

 sharp edg« or bead, anteorbital foramen nearly circular above and con- 

 tinued below as a narrow slit. Maxillary plate forming outer wall of 

 foramen not produced anteriorly into a pointed ^process (cf. Sigmodon). 

 Posterior border of palate produced behind last molars, a deep pit inter- 

 vening on either side ; post-palatal notch narrow, with parallel sides, and 

 nearly straight, transverse, anterior border. Hind legs short, but feet 

 very long and large (much as in Fiber), with obliquely-set long toes, 

 densely pilous above, but soles perfectly naked, granular, with one long, 

 narrow, postero-internal tubercle (as in Mts), and five small ones. Lat- 

 eral toes very unequal in length, the fifth reaching to the penultimate 

 joi-nt of the fourth (cf. Sigmodon); all the toes have a slight but evident 

 basal webbing. Pore feet small, not half as long as hinder, pilous above; 

 palms perfectly naked. Ears small, little overtopping the fur, hirsute 

 both sides, with a fluffy tuft on the concavity. Nasal pads more notice- 

 able than in other sections. Tail long, about equalling head and body, 

 scant-haired, especially above where the dermal scales as well as the ver- 

 tebral annuli are visible. Fur glossy, but coarse from the number of 

 bristly hairs. Whiskers sparse and short, exceeding, however, those of 

 Sigmodon, though falling short of those of Hesperomys proper. Exceeding 

 in size any other known North American species of Hesperomys, and with 

 the general appearance of Sigmodon or even Mm." (Coues.) 



Hesperomys (Oeyzomys) palustris (Harl.) Wagner. 

 EicE-riBLD Mouse. 



1837- Mus palustris, Harlan, Am. Journ. Sci., xxxi, 1837, 386 (New Jer- 

 sey). 



1843. Hesperomys palustris, Wagner, Suppl. Schreb., iii, 1843, 543. — Le 

 Conte, Proc. Acad. Nat. Sci., Phila., vi, 1853, 410.— Allen, Bull. 

 Mus. Comp. Zool., ii, 1870, 182 (Florida). 



1853: Arvicola oryzivora, Aud. & Bach., Q. N. A., iii, 1853, 214, pi. 144, 

 fig. 3. 



1857. Hesperomys (Oryzomys) palustris, Baird, M. N. A., 1857, 482 (Georgia 

 and South Carolina).— Coues, Proc. Acad. Nat. Sci., Phila., 1874, 

 184; Hon. N. A. Rodentia, 1877, 113. 



