498 Transactions.— Zoology. 
- to the tenth, in which the same is only 1:50 inch high. They continue, 
however, to possess the same truncated apex with a downward slope from 
front to back, getting at their starting point from the arch gradually larger, 
that on the fourth caudal vertebra being here the largest of the whole series 
of vertebre. The metapophyses also gradually diminish and assume, instead 
of the former flattened form, now a stouter appearance with a more outward 
direction of the pomt. The same diminution in size is observable in the 
lower transverse proccess, which on the eighth caudal vertebra forms only a 
very small ridge, but has entirely disappeared on the ninth. 
The tenth vertebra is very much laterally compressed. The eleventh 
assumes a rounded form, which becomes more squared in the 12th, after 
which the rest have a nearly quadrangular form to the last. The last cau- 
dal vertebre, beginning with the tenth, have a well excavated channel 
running along both sides of the vertebra. I may here observe that the 
last chevron bone, as well as the seventeenth and nineteenth vertebrz, are 
missing in this skeleton. 
Ribs. 
There are nine ribs on each side, of which seven possess two articulat- 
ing processes. The first, which is the shortest of the whole series, is also 
the broadest. It is thick and flattened throughout. It articulates by a 
distinct capitular process with the body of the seventh cervical vertebrze, and 
above by an excavated articular surface, with the transverse process of the 
first thoracic vertebra. 
From the second to the sixth the ribs gradually lengthen, the sixth 
being the longest, after which they decrease again. The second has still 
the flattened appearance of the first, but in a lesser degree, after which 
they assume all nearly the same shape, the upper portions below the arti- 
culations or articulator having a prismoid form, which is most pronounced 
in the middle of the ribs, where they are also the most constricted, the edge 
being on the inner side. They then widen and flatten to their lower 
extremity. 
The second to the seventh ribs inclusive have, like the first, two articula- 
tions—a distinet capitular process for articulation with the vertebra in front, 
and an excavated articular surface slightly raised round the edges, into 
which the transverse process fits. 
The eighth and ninth ribs have only one excavated surface, articulating 
with the end of the transverse process. 
The greatest length of each rib, measured in a straight line, is :— 
Ft. In. 
First Fl Ken i des Vis Wo 
Second  ... e: ive ea $ we se 
