USNM—United States National Museum, Washington, D. C.
The following measurements of the skull are listed in the tables:
Condylobasal length.—The shortest distance between the anteriormost projections of the premaxillaries and a line touching the posterior surfaces of the exoccipital condyles.
Length of nasals.—The distance from the most anterior projection of the nasal bones to the most posterior projection of a nasal bone.
Zygomatic breadth.—The greatest distance across the zygomatic arches, at right angles to the long axis of the skull.
Squamosal breadth.—The greatest distance between the mastoidal processes of the squamosal.
Length of rostrum.—The shortest distance from the shallow notch that lies lateral to the hamulus of the lacrymal bone, to the tip of the nasal on the same side of the skull.
Breadth of rostrum.—The greatest width of the rostrum, anterior to the maxillae, transverse to the long axis of the skull.
Alveolar length of upper maxillary tooth-row.—Distance between the anterior margin of the alveolus of the first cheek-tooth and the posterior margin of the alveolus of the last upper cheek-tooth, on one side of the skull.
Least interorbital breadth.—The least distance across the frontal bones at the interorbital constriction as seen in dorsal view.