10 
heel of the sectorial is well developed. The tubercular is very 
small. 
The form of the skull is short and wide; the zygomata are 
much expanded, and the profile is very convex. The muzzle is 
short, and the orbits are rather large. The interorbital region is 
wide and convex, and the postorbital processes are robust, acu- 
minate, and directed downwards. The infra-orbital foramen is 
very large. The apices of the premaxillary bones are elongate, 
but do not reach the frontals. The nasals are rounded posteriorly. 
The sagittal crest is prominent, and the inion elevated. The 
posttympanic process is short, and the paroccipital is short and 
is directed backwards. The cranium is constricted behind the 
orbits. The mandibular ramus is low posteriorly, and the ante- 
rior inferior flange is well-developed, but not large. 
Measurements. M. 
Length of skull on base F 2 : 3 . 140 
Width of skull, measured below .. . ‘ o) Ad 
Length of palais , ‘ . 060 
Width of palate between posterior ales of sec- 
torials A 3 B : - 062 
Width of palate eisiien, canines . ; ‘ - 026 
Length of skull to front of orbits (axial) . . 050 
Vertical diameter of orbit. 3 : ‘ . 031 
Interorbital width (least) : : . . 045 
Elevation of inion from foramen . é 4 - 032 
Length of inferior molar series. : ‘ - 050 
Length of inferior sectorial . : . F . 018 
Length of base of inferior first premolar. - 055 
Depth of ramus at sectorial . : : 7 . 016 
Depth of ramus at first premolar . fo” Be - 021 
Depth of ramus at flange ‘ . : - 026 
From the Truckee beds of John Day River, Oregon. 
CANIDA. 
The range of variation presented by the species of Canidzx in- 
cludes several generic divisions, recent and extinct. These genera 
are, however, as closely intergraded as are those of the cats, and 
their definite characters are subject to occasicnal failure from ab- 
