1915.] Matthew and Granger, Lower Eocene Wasatch and Wind River Faunas. PAs. 
The feet display the characters of Viverravinee 
as outlined by Matthew in 1909. The ungual 
phalanges are long, not strongly curved or com- 
pressed as in the Miacinee, but as in all Eucreodi 
they are unfissured at the tips. The symmetry 
of the pes is paraxonic, mt. III and IV paired. 
The hallux is not divergent as it is in Vulpavus, 
nor have the cuneiforms the curious oblique facets 
noticed in that genus; in this and other respects 
they are more like those of modern Carnivora. 
The astragalus has a considerable cuboid facet, a 
very oblique and shallow grooved trochlea, the 
outer crest more distinct than in Miacine. The 
forward movement of the tibia is limited by two 
well marked facets upon the neck of the astra- 
galus; one for the internal malleolus upon its inner 
slope, the other for the anterior face of the tibia 
upon the outer slope of the neck, and continuous 
with the trochlea. The astragalar foramen limits 
the play of the tibia posteriorly so that the motion 
at this joint is not extensive. The movement of 
the fibula on the caleaneum is similarly limited. 
The patellar trochlea of the femur is very long, 
the patella small and flat, not elongate; the con- 
dyles of the femur face posteriorly. The fibula is 
unusually heavy; tibia and fibula moderately long. 
The proximal and second row of phalanges are of 
moderate depth and permit extended movement 
on the metapodials; the second phalanx is slightly 
asymmetric but not excavated for a retractile 
claw. 
The unciform is broad and low, with a fairly 
wide lunar facet, whose angle with the cuneiform 
facet is very slight. ae 
The construction of the pes in this genus dif- 
fers very considerably from that in the Miacine, 
although it has the essential family features. It 
affords an interesting comparison with the pes of 
Oxyena from the same formation. 
\ 0 
CY} Zp AN 
Fig. 18. Didymictis alti- 
dens, tibia and fibula, natu- 
ral size, anterior and distal 
views, No. 14781, Lost Cabin 
beds, Wind River Basin. 
