MORPHOLOGY OF BAROSAURUS LENTUS. 
37 
Femur (PI. VII; Text Fig. 9). — A number of fragments of a femur are present. 
Of these, three have been assembled to form the proximal end. This gives a clue to 
the enormous proportions of the bone, which are about one and three-quarters those 
of Diplodocus as estimated from Hatcher's figures (op. cit., Figs. 15-17). The same 
relative dimensions are true also of the distal end of the tibia, which is likewise pre- 
served. A sketch of the relative proportions is here shown (Text Fig. 9). The 
measurements as thus indicated follow : 
Measurements of the Femur 
Barosaurus 
lentus 
mm. 
Diameter at AB, transverse 395 
Diameter at AB, thickness 170* 
Circumference at AB 950 
Length ( ?2525.8) 
Average ratios : Barosaurus lentus and Diplodocus camcgiei 
* Crushed. 
Diplodocus 
carnegiei 
mm. 
230 
137-5 
1468.5 
Ratios 
1.72 
1-23+ 
(1.72) 
147 
Figure 10. — Tibia of Barosaurus and Diplodocus camcgiei, distal ends 
superimposed. One-sixth natural size. Solid line, Barosaurus; dotted 
line, Diplodocus, from the photograph by Hatcher 1901, Plate XI, Figure I. 
A, astragalar facet. 
This immense length, 8 feet 2j4 inches, is manifestly improbable, but is about 
what the length would be were the known ratios with Diplodocus carried out. The near 
approximation of lengths of the dorsal and caudal vertebrae in the two genera would 
lead one to infer a similar correspondence in the femoral length, despite the greatly 
enlarged cervicals in Barosaurus, the latter implying possibly elongated fore limbs as in 
Brachiosaurus, not hind limbs as well. 
The distal end of a femur, probably the left, is also present. Although only its 
anterior face is preserved intact, the inner condyle is indicated and also the beginning 
of the outer. The proportions which may thus be ascertained would make it about 
350 mm. across as compared with about 250 for D. camegiei, giving a ratio of about 
1.40, less than that of the proximal end. These measurements are, however, inaccurate 
