34 THE SAUROPOD DINOSAUR BAROSAURUS MARSH. 
shows an increased thickness and rugosity, as though continued somewhat in cartilage. 
Areas for muscle attachment are also visible around the margin, especially toward the 
posterior end on the outer side. The general thickness of the bone is more or less 
uniform, rarely exceeding 19 mm. at mid length to 12 mm. toward the anterior end. 
The knob-like posterior end, on the other hand, is 68 mm. thick. The outline drawn to 
scale with that of Diplodocus carnegiei is here shown (Text Fig. y). 7 Were the 
posterior portion of the Barosaurus sternal intact, its length would more nearly equal 
that of D. carnegiei. 
Measurements of the Sternal 
Barosaurus Diplodocus 
lentils carnegiei* Ratios 
mm. 
Anteroposterior diameter 485! 540 0.90 
Greatest transverse diameter 250 310 0.80 
Length, median articulation 150 280 0.70 
Length, coracoid articulation 160 140 1. 14 
Index, length to breadth 1.92 : 1 i-74 : 1 
* From Holland's figure, 
t As preserved. 
Appendicular Skeleton 
fore limb and girdle 
The only portion of the fore limb or its girdle present is a fragment which has 
been identified as of a scapula, largely through a process of elimination, as the outline is 
only in very small part preserved. 
Scapula (see PI. VII).- — This bone consists of a portion 810 mm. long by 22.5 mm. 
wide. But two portions of the outline remain, one somewhat irregular at the distal end, 
and a small portion of the almost straight lateral border. The bone is fairly massive, 
thinning toward the margin, but in no way remarkable, judging from the very inadequate 
portion preserved. 
HIND LIMB AND GIRDLE 
The hinder extremities are represented by a number of elements, none of which 
unfortunately is complete. 
Ilium (see PI. VII). — Of the ilium there are present a number of marginal frag- 
ments, including a portion of the acetabulum and the pubic peduncle. Further 
description, however, is of little value. 
Pubis (PL VI, Fig. 2; Text Fig. 8). — A right pubis is present, excellently pre- 
served except for its distal end, of which a considerable portion is missing. A portion of 
the proximal end is also eroded away, but this is relatively inconsiderable. A scale draw- 
ing has been made superposed upon that of Diplodocus carnegiei enlarged from Hatcher's 
figure (op. cit. PI. I, Fig. 1). The pubis of Barosaurus was the larger, although the 
preserved portion is actually the shorter of the two. The ratio of shaft widths, about 
the only absolute measurement, is essentially that of the femora and tibiae, about 1.70, 
actually 1.69. Were the same ratio maintained in the relative lengths, that of Barosaurus 
7 W. J. Holland, The Osteology of Diplodocus Marsh. Mem. Carnegie Mus., Vol. 2, No. 6, 1906, 
Figs. 25, 26. 
