ROMEROLAGUS. LEPUS. 413 
Geogr. Distr. Mt. Popocatepetl, State of Mexico, and Mt. Iztac- 
cihuatl ? Mexico. 
Genl. Char. Those of genus. 
Color. Upper parts, collar, and sides grayish brown and black, 
suffused with yellowish; chin and belly smoky gray washed with 
buff; feet buffy yellow. 
Measurements. Total length, 311; tail vertebre, 0; hind foot, 
53; ear from notch (skin), 36. Skull: occipito-nasal length, 48; 
Hensel, 38; zygomatic width, 25; across orbital processes, 13; palatal 
length, 20; length of mandible, angle to symphysis, 31; height at 
coronoid process, 23. 
84. Lepus. 
Eepus Linn., Syst. Nat., 1, 1758, p. 57; 1, 1766, p. 79. Type Lepus 
timidus Linnezus. 
Hydrolagus Gray, Ann. Mag. Nat. Hist., 3d Ser., xx, 1867, p. 221. 
Silvilagus Gray, Ann. Mag. Nat. Hist., 3d Ser., xx, 1867, p. 222. 
Tapett Gray, Ann. Mag. Nat. Hist., 3d Ser., xx, 1867, p. 224. 
Macrotolagus Mearns, Science, 1, 1895, p. 698. /d. Proc. U.S. Nat. 
Mus., 1896, p. 552. 
Microlagus Trouess., Cat. Mamm. vivent. quam fossil, 1897, fasc 3, 
p. 660. 
Limnolagus Mearns, Science, N.5S., v, 1897, p. 393. 
Skull high, superior outline much curved, especially at occipital 
region; postorbital processes in the majority of species long, more or 
less divergent, flanking a deep wide notch, their posterior extremities 
not completely fused with skull; (exceptions to this are the swamp 
hares which have this process ankylosed to the cranium by its tip, or 
its internal margin); all the openings of the skull are large; facial sur- 
face of the maxilla reticulated; orbits very large, meeting in the mesial 
line of the cranium; teeth more numerous than in any other family of 
rodents; second pair of upper incisors small, situated behind the chief 
pair; the latter is grooved deeply in front, and all are deeply implanted 
in the skull and lower jaw; molars rootless; third upper molar minute; 
last lower molar larger, but still much the smallest of the lower series; 
palate a mere bridge between molars. The scapula ends in a process, 
which has near its termination a branch directed at right angles to the 
axis; tibia and fibula always ankylosed; fore feet with five toes, hind 
feet with four. A patch of hair covered skin on inner surface of cheeks 
extending backward from the angle of mouth. Hind legs elongate, in 
some species greatly so; ears very long; tail rudimentary. 
