30 
THE SAUR0P0D DINOSAUR BAROSAURUS MARSH. 
transverse bar of bone. The haemal canal is triangular and extends a little more than 
one-sixth the length of the bone. The bone is laterally compressed, dagger-like, with 
rather acute front and rear margins, especially in the distal third of the front and half 
of the rear edge. The articular facet is continued down the posterior side as though 
there had been considerable backward inclination of the bone. 
Figure 3. — Chevron V, rear aspect. One-fourth natural size. Note the 
slight asymmetry, he, haemal canal. 
Measurements of Chevron ca. V 
Barosaicj-us 
lentus 
mm. 
Length 348 
Width of base 155.7 
Width of mid length 36 
Antero-posterior diameter of blade 63 
Haemal canal, height 55 
" width 39 
Chevron ca. IX (PI. VI, Fig. 6; Text Fig. 4).— A second chevron is present 
which can not have been far from the ninth. The bearing surface is nearly as broad as 
before, the haemal canal larger, but the blade of the chevron is materially shorter. The 
last seems to be pathologic, as there is a foramen (see PI. VI, Fig. 6, f) passing 
through the blade below and at right angles to the haemal canal. This aperture is a 
longitudinal slit-like perforation with rounded margins, penetrating not the main mass 
of the bone but the two ridges which continue downward on either side of the haemal 
canal on the posterior margin of the bone. This ridge is broken away on the left side 
of the bone, but is complete on the right. Whether there were two foramina, or 
