NOTES ON THE CANID& OF THE WHITE RIVER OLIGOCENE. = BOO 
The mesocuneiform is a very small, wedge-shaped bone, broadest dorsally and thin- 
ning to an edge on the plantar side. The nayicular facet is concave and yery different 
from the curious oblique surface which we find in Dinictis, As is well-nigh universal 
among the Carnivora, the proximo-distal diameter of this bone is much less than that of 
either of the two adjoining cuneiforms, an arrangement which allows the head of the 
fourth metatarsal to rise above the level of the first and third. 
The ectocuneiform is, as usual, much the largest of the three, though it is not so 
large proportionately as in Dinictis. The shape of this element is very much as we find 
it in Canis, but with certain minor differences. Thus, the proximal end is less extended 
in the dorso-plantar diameter, and the navicular facet is more concave; the plantar 
tubercle has a more constricted neck and enlarged, rugose head; the facets on the tibial 
side for the mesocuneiform and second metatarsal, and on the fibular side the inferior 
facet for the cuboid are more distinctly developed, while the distal facet for mt. iii is more 
concave and has a shorter plantar prolongation. 
As a whole, the character of the tarsus is rather more machairodont, or viverrine, 
than canine. A conspicuous difference from the tarsus of the modern Canidw, is to be 
seen in the fact, that the articulations which in the latter are nearly plane (e. g., the 
cubo-calcaneal) in Daphenus retain their more primitive concayo-conyexity. 
The metatarsus consists of five members, which are longer and relatively more 
slender than the metacarpals, though an exact comparison between the two cannot yet be 
made, because the collection contains no specimens in which both metacarpals and meta- 
tarsals are represented by anything more than fragments. 
The first metatarsal is considerably longer and stouter than the corresponding meta- 
carpal. In this case we can determine the true proportions, for of the species to which 
the finely preserved hind foot (Pl. XX, Fig. 21) belongs, D. hartshornianus, we also 
possess a pollex, though associated with a different specimen. The almost exactly similar 
skulls of the two individuals show that the animals were of approximately equal size. 
The head of mt. iis enlarged in both the transverse and dorso-plantar diameters, and bears 
a roughened tubercle upon the plantar side. The proximal facet, for the entocuneiform, 
is large, and strongly convex antero-posteriorly, nearly plane transversely; no other 
facets are visible on the proximal end. The shaft is slender and arched toward the dorsal 
side; in section it is transversely oval, expanding somewhat at. the distal end, where the 
breadth is increased by the prominent tubercles for the lateral ligaments. The distal 
trochlea is small, but well developed, and of irregularly spheroidal shape, with plantar 
carina. The first metatarsal of Dinictis is like that of Daphenus, and certain viverrines, 
such as Cynogale, also have a hallux of much the same proportions, but in all the 
recent Canidae, with the exception of certain domesticated breeds, mt. 1 is reduced to a 
nodule. 
