EDENTATA OF THE SANTA CRUZ BEDS. 22Q 



No. No. No. No. 



15,545- 15,160. 15,597. 15,155- 



Ulna, width at sigmoid notch 022 .020 .020 



Metacarpal II, length -0295 



" " width of proximal end .017 



" " " " distal end .0115 



" " thickness of distal end .016 



Save in size, the pelvis differs little from that of H. longiceps. The ilium 

 is quite long and broad and runs nearly parallel with the sacrum, though 

 somewhat everted at the anterior end ; the acetabular border is external, 

 making the broad gluteal surface dorsal, as in all this group. The ischium 

 is much shorter than the ilium and the sacro-sciatic foramen is a longi- 

 tudinal oval. The pubis is a slender, compressed rod and the symphysis 

 is short; the obturator foramen is triangular, with principal diameter 

 parallel with the pubis. 



The femur (Plate XLI, fig. 5) is relatively longer and more slender 

 than in H. longiceps, though there is little difference in appearance ; the 

 head is small and hemispherical and on its postero-internal side, hardly 

 visible from the front, is the pit for the round ligament, a large, irregular 

 depression, which does not extend to the margin of the articular surface ; 

 the great trochanter is less prominent than in H. longiceps and the notch 

 between this process and the head is shallower; the second trochanter is 

 extended well down upon the inner side of the shaft, while the third tro- 

 chanter has a little more proximal position than in the larger species. 

 The shaft is less antero-posteriorly compressed than in the latter and its 

 surfaces are more convex. The distal tuberosities are less developed. 



The patella is long, narrow and thin ; its distal prolongation is much 

 narrower than in H. iongiceps, remarkably so in some individuals. 



The tibia and fibula (Plate XLI, fig. 6) differ little, except in size, from 

 those of H. longiceps, but much individual variation, due partly to differ- 

 ences of age, is observable ; the only feature calling for notice is the 

 flatness of the astragalar facet of the tibia. 



The pes (Plate XLI, figs. 1-3, 7) is of a type entirely similar to that of 

 H. longiceps, differing only in a few details, but the variations in the form 

 of the calcaneum and astragalus are remarkable, no two specimens of 

 these bones being in all respects alike. The astragalus has the narrow, 

 elongate shape seen in all the species of the present genus, but the tro- 

 chlea is much less distinctly grooved than in H. longiceps and is less 



