SINCLAIR: MARSUPIALIA OF THE SANTA CRUZ BEDS. 369 



probably sharp. A hood is developed to about the same extent as in 

 Borhycena. The subungual processes are large and an ungual foramen is 

 present. 



The greater part of both halves of the pelvis is preserved (PI. XLIX, 

 figs. 3; PI L, fig. i), but, unfortunately, the pubes are almost entirely 

 missing. The peduncular portion of the ilium is considerably heavier 

 than in Thylacynus, supporting a very large tubercle for the origin of the 

 rectus femoris muscle. The gluteal surface is broadly expanded, but with 

 little trace of the longitudinal grooving noticeable in the recent genus. 

 The ilio-pectineal eminences are very large and rugose. The ischium is 

 incomplete posteriorly, lacking the ischial tuberosity, but both acetabular 

 and post-acetabular portions are heavier than in Thylacynus. The ischial 

 spine is small. The pubis, so far as preserved, is narrower antero-pos- 

 teriorly than in the recent genus. The acetabulum is large and deep. 

 Beneath the acetabular notch, the border of the obturator foramen is 

 exceedingly sharp. Posteriorly, it assumes the usual convex contour. 



The femur (PI. L, figs. 2, za], although of almost the same length as 

 in Thylacynms, is much heavier. The large hemispherical head is sup- 

 ported on a long neck. The greater trochanter rises above the level of 

 the head, from which it is separated by a broad interval. The digital 

 fossa is long and deep and the intertrochanteric ridge high and narrow. 

 The lesser trochanter is slightly larger than in Thylacyims and is separ- 

 ated farther from the head. The shaft is straight, circular in cross-section 

 at the middle, but flattened antero-posteriorly at either end. Above the 

 condyles, the distal end is semicircular in cross section. The condyles 

 have about the same posterior extension as in Thylacynus, but are much 

 flatter transversely, resembling BorJiyczna. The intertrochanteric fossa is 

 wider and deeper, and the rotular groove broader and shallower than in 

 Thylacynus. 



The patella (PI. L, figs. 4, 4) is a stout, wedge-shaped element, broad 

 at the proximal end, but tapering distally to a thin edge. The rotular 

 surface is irregularly pentagonal in outline, concave in vertical section 

 and convex transversely. The anterior surface is rugose for tendinous 

 attachment. 



The tibia (Pis. XLIX, fig. 4 ; LI, fig. 2), unlike that of Thylacymts, 

 is considerably shorter than the femur. The head supports two broad, 

 flat surfaces for articulation with the femoral condyles. The spine is 



