384 PATAGONIAN EXPEDITIONS: PALAEONTOLOGY. 



fourth is the longest. The shafts are more slender than that of the pollex 

 and are slightly arched and more or less compressed in the dorso-palmar 

 plane. 



The structure of the pelvis (Pis. LVII, figs i, ia; LVIII, figs, i, 7, 7*7) 

 is important from the bearing it has on the thylacyne affinities of Clado- 

 sictis. The anterior margin of the pubic symphysis is slightly damaged 

 in the otherwise nearly complete pelvis of C. liistratus (No. 15,170). The 

 anterior pubic border is sharp, without trace" of supporting structures for 

 epipubic bones. The pubic symphysis is closed, as in Thylacynus, so it 

 seems probable that, if epipubic elements were present, they must have 

 been vestigial cartilages, as in the latter genus (cf. text-fig. 3). The pe- 

 duncular portion of the ilium is more attenuated than in Frothy lacynus, 

 supporting heavy recti tubercles. The gluteal surface is broad and smooth 

 with even less trace of muscular flutings than in Frothy lacynus. The 

 iliopectineal eminences are large. The ischial tuberosities are less pro- 

 nounced than in Thylacymis. The obturator foramina are large and oval 

 in outline, with the posterior border emarginated by an anteriorly directed 

 prominence. 



The same lack of proportion between the lengths of skull and femur, 

 which was mentioned in the discussion of the genus BorJiycena, is observ- 

 able to even a greater extent in the case of Cladosictis. The femoral shaft 

 has a gentle sigmoid curvature, expanding at either end to about the same * 

 extent and in much the same manner as in Borhycena. The greater tro- 

 chanter and head reach the same elevation. The lesser trochanter is 

 prominent. As in Borhycena, the inner condyle is somewhat wider than 

 the outer one. The intercondylar notch is deep and narrow, leading an- 

 teriorly into a wide, shallow rotular groove, the margins of which are more 

 acute than in Thylacynus (cf. text-fig, i, c]. 



An ossified patella has not been found in association -with any of the 

 skeletal material of Cladosictis in the collection, and has accordingly been 

 omitted in the restoration. 



The tibia (PI. LVIII, figs. 2, 8) resembles that of Frothy lacynus, differ- 

 ing, however, in being slightly narrower distally and in having the distal 

 fibular facet less obliquely placed. The shaft is straight, in contrast with 

 the curvature of the tibial shaft in Thylacymis (text-fig, i, d]. The cnemial 

 crest is poorly differentiated, as in Frothy lacynus, extending more than 

 half way down the shaft. Distally, the tibia exhibits a trochlear surface 



