i 
448 Transactions.—Z oology. 
The bodies of the thoracic vertebre up to the seventh have a flattened 
lower surface, after which a keel starts on the eighth, which is well pro- 
nounced on the ninth and tenth. 
Lumbar vertebra. 
The ten lumbar vertebre resemble each other very much in form. 
Gradually they become more elongated, the first having an antero-posterior 
length of 4-55 inches, and the eighth of 6:30 inches, after which they 
shorten again a little. They possess all a median keel, and are compressed 
in the centre below the transverse process. The spinous processes are 
large and high, increasing to the eighth, which is 11:50 inches high, after 
which they slightly decrease. The arches arise from the centre of the 
bodies, thus differing from Berardius and Epiodon, where they have a more 
anterior position. l 
Caudal vertebre. 
There are nineteen caudal vertebræ, of which the first ten have a deep 
channel running along their lower surface. The spinous processes gradu- 
ally lose in height, that of the tenth vertebra consisting only of a slight 
excrescence. 
The lower transverse processes also shorten by degrees, so that in the 
sixth they are represented by a small horizontal ridge, which is only faintly 
indicated in the seventh. In the eighth, ninth, and tenth vertebre, all ` 
signs of such processes are missing, but they are also strongly laterally com- 
pressed. There are nine chevron bones, of which the last is missing. With 
the eleventh vertebra the second series of the caudal vertebræ begins, which 
in form greatly resemble those of the New Zealand Epiodon. 
Ribs. 
There are ten ribs on each side, of which seven have two articulations, 
and the three last only one. The first is the shortest of the whole series, 
with the exception of the last ; it is also the broadest. There is scarcely a 
sign of an articular process for its articulation with the seventh cervical 
vertebra, and only a very slightly marked articular surface for the trans- 
verse process, both being indicated by a small indentation on the edge 
of the head of the rib. 
The second rib has the same flattened form as the first; it is longer, 
and both articulating processes are better defined. 
From the second to the sixth rib they gradually lengthen, after which 
they diminish again a little until we reach the tenth, which is the shortest 
of the whole series. The third, fourth, fifth, sixth, and seventh ribs have 
all well defined articulating processes, and nearly the same form, flattened 
at and near their head, after which, for nearly one-third of their total 
