248 PATAGONIAN EXPEDITIONS I PALAEONTOLOGY. 



larger proximal facet for the ulna and a less prominent bicipital tubercle, 

 and the inner border of the distal half of the radial shaft is somewhat more 



distinct. 



MEASUREMENTS. 



Humerus, length 1 29 Ulna, width at sigmoid notch 0195 



" width of proximal end 037 " " of distal end oio 



" " " trochlea 027 Radius, length 1 1 1 



" over epicondyles 050 " width of proximal end 019 



Ulna, length 128 " " " distal end 023 



" of olecranon 020 " greatest width of shaft 020 



The pelvis (see text-figure 21, p. 170) is very similar to that of H. 

 elongatus, with a few differences. The ilium is somewhat more everted, 

 making the acetabular border more concave, and has a more curved 

 crista ; the acetabulum is smaller and more circular and the fossa for the 

 round ligament is less extensive ; the obturator foramen is of a different 

 shape, the dorso-ventral diameter being greater and the antero-posterior 

 diameter less ; the descending process of the ischium, behind the obturator 

 foramen, is more slender and the symphysis appears to be somewhat 



shorter. 



MEASUREMENTS. 



Pelvis, length 190 Acetabulum, antero-posterior diameter .032 



" greatest width 225 " dorso-ventral diameter . . .027 



Ilium, length 114 Ischium, length 076 



" greatest width 080 Symphysis, length 039 



In the femur (Plate XLII, fig. 7) the head is more oblique, directed 

 more proximally and rising higher above the level of the great trochanter 

 than in H. elongatus ; the pit for the round ligament is smaller and shal- 

 lower ; the second trochanter is rather more prominent and the third tro- 

 chanter broader proximo-distally ; the condyles are of similar shape, but 

 even less prominent, so that the notch between them is smaller. 



The tibia (Plate XLII, fig. 8) is almost a copy pf that of H. elongatus, 

 on a somewhat reduced scale ; the facets for the femoral condyles are a 

 little more closely approximated and the spine slightly more pronounced, 

 while the cnemial process is even more reduced. The shaft and distal end 

 differ in no significant way, but the postero-internal margin of the astraga- 

 lar facet is more prominent and the intercondylar ridge less so. 



The fibula (Plate XLII, fig. 8) differs from that of H. elongatus rather 

 more than does the tibia ; the proximal end is thicker antero-posteriorly 



