SINCLAIR: MARSUPIALIA OF THE SANTA CRUZ BEDS. 399 
appears to have been proportionately larger than in Sarcophilus or Thy - 
lacy mis. As in Cladosictis , this surface is divided by a sharp keel into a 
small inner and a large outer rotular groove, indicating an enlargement of 
the outer condyle of the metacarpal, which produced a deflection of the 
phalanges of the pollex toward the inner side of the foot. The remaining 
proximal phalanges are short and stout, with straight shafts and prom- 
inent tuberosities for the annular ligament. The distal trochleae are 
without trace of the median keel-like structures observable in Sarcophilus, 
resembling in this respect Thylacynus. The proximal articular surfaces 
of the phalanges of the second row are prolonged dorsally by the devel- 
opment of tongue-like processes fitting between the condyles of the prox- 
imal phalanges, indicating that these two sets of elements were carried 
with respect to each other at a considerable angle. The unguals are la- 
terally compressed, sharp-pointed and without terminal clefts. Hoods are 
developed to about the same extent as in Sarcophilus and Dasyurus 
maculatus. 
With the exception of the claw of the second digit, the figure (PL LIV, 
fig. 5) shows the original association of the phalanges of the manus. The 
ungual interpreted as that of the second digit lay in the matrix above the 
fifth metacarpal. 
In the pes (PI. LIV, fig. 6), the trochlear surface of the astragalus is 
short and almost flat transversely. Distally, the tibial trochlea is pro- 
duced on the upper surface of the neck. The neck is proportionately 
longer than in Sarcophilus and Thylacynus and the head is less obliquely 
placed than in those genera. The calcaneal and sustentacular facets are 
like those of Prothylacymis (PI. LIV, fig. 2 d) in shape and position. Two 
minute astragalar foramina are present. The calcaneum has the tubercle 
for the attachment of the calcaneo-cuboidal ligament greatly enlarged and 
grooved. The calcaneum carries a facet for articulation with the fibula, 
which is confluent with the ectal facet for the astragalus. The susten- 
tacular facet is concave and is broadly separated from the former, unlike 
the condition in Sarcophilus and Thylacynus. The tuber calcis is rela- 
tively shorter than in those genera, occupying somewhat less than one 
half the total length of the calcaneum. The remaining tarsals agree 
closely in shape and in the arrangement of the articular facets with those 
of Prothylacynus and do not call for separate description. 
The hallux, when brought into articulation with the entocuneiform, is 
