A Synopsis of the North American Lagomorpha

legs scarcely longer than forelegs; ears short, approximately as wide as high; no postorbital process on frontal; rostrum slender; nasals widest anteriorly; maxilla not conspicuously fenestrated; jugal long and projecting far posteriorly to zygomatic arm of squamosal; no pubic symphysis; one less cheek-tooth above, the dental formula being i. 2/1, c. 0/0, p. 3/2, m. 2/3; second upper maxillary tooth unlike third in form; last lower molar simple (not double) or absent (in the extinct genus Oreolagus); cutting edge of first upper incisor V-shaped; mental foramen situated under last lower molar.

Genus OCHOTONA Link--Pikas

Revised by A. H. Howell, N. Amer. Fauna, 47:1-57, August 21, 1924.

1795. Ochotona Link, Beyträge zur Naturgesch, I (pt. 2):74. Type, Lepus ogotona Pallas.

Characters.--Five teeth (excluding incisor) in lower jaw; first cheek-tooth (p3) with more than one re-entrant angle; columns of lower molars angular internally; transverse