localities are shown on the map will
permit a person to associate any symbol on a map with its corresponding
place name.

Measurements are in millimeters unless otherwise indicated. Capitalized
color terms are after Ridgway (Color Standards and Color Nomenclature,
Washington, D. C., 1912), and uncapitalized terms refer to no particular
color standard. Several of the drawings of skulls were reproduced
originally in the "Mammals of Nevada" (Hall, 1946) and I am grateful to
the University of California Press for permission to use them here.
Those drawings were made by Miss Viola Memmler. The other drawings are
the work of Mrs. Frieda Abernathy, Mrs. Diane (Danley) Sandidge, and
Mrs. Virginia (Cassel) Unruh. Initials on the drawings identify the
individual's work. The study here reported upon was aided by a contract
between the Office of Naval Research, Department of the Navy, and the
University of Kansas (NR 161-791). Also, assistance with some of the
field work was given by the Kansas University Endowment Association and
by Dr. Curt von Wedel. For the corrected dates on several publications I
am indebted to Dr. A. Remington Kellogg. For assistance with the
organization of the data for the present account I am grateful to
several persons, especially to my wife, Mary F. Hall, and to Dr. Keith
R. Kelson.

Order LAGOMORPHA--Hares, Rabbits and Pikas

Families and genera revised by Lyon, Smithsonian Miscl. Coll.,
45:321-447, June 15, 1904. For taxonomic status of group see Gidley,
Science, n. s., 36:285-286, August 30, 1912.

The order Lagomorpha is old in the geological sense; fossilized bones
and teeth of both pikas and rabbits are known from deposits of Oligocene
age and even at that early time the structural features distinguishing
these animals from other orders were well developed.

A noteworthy character of the order is the presence of four upper
incisor teeth (instead of only two as in the Rodentia); also, the fibula
is ankylosed to the tibia and articulates with the calcaneum. Each of
the first upper incisors has a longitudinal groove on its anterior face.

All lagomorphs are herbivorous. They eat principally leaves and
non-woody stems although the bark of sprouts and bushes is taken as
second choice by rabbits and hares.

Correlation of structure and function is well illustrated among the
lagomorphs by the means which the different species employ to detect and
escape from their enemies. A gra