96 MR. W. H. FLOWER ON THE OSTEOLOGY OF 
7 belong to the cervical, 13 to the thoracic, and 21 to the lumbo-caudal region. When 
the vertebre are placed in order, with their bodies in contact, the whole column mea- 
sures 38°8". 
The cervical region, as in Platanista, occupies a larger proportional space than in 
most other Cetaceans, being 33" long, or ;§3a of the whole column. In a common Por- 
poise, measured for the purpose of comparison, it is but ~jO>- All the vertebra are 
distinct, as in Platanista, Beluga, and Monodon alone among toothed Whales. 
The atlas (Pl. XXVII. fig. 1), very large for the size of the animal, greatly resembles 
that of Platanista, but is higher in proportion to its breadth. Its neural arch is strong, 
and has on its upper surface a slight longitudinal ridge representing the spine. ‘The 
base of the arch is not perforated as in many Cetaceans, and the groove for the sub- 
occipital nerve is but slightly marked, On each side, between the anterior and pos- 
terior articular surfaces, are two rounded eminences, the rudiments of an upper and 
lower transverse process. In Platanista there is only a single intermediate process (which 
Eschricht considers to represent the lower process), but it is developed to a much greater 
length. In Beluga both processes are present as in Jnia, and upon corresponding parts 
of the surface of the bone. As in the other Odontoceti having a free atlas, there is a 
strong process developed from the hinder edge of the lower arch of the bone, which 
passes under and articulates with the inferior surface of the axis (see Pl. XXV. fig. 2). 
This is bifid at the extremity, and much more powerfully developed than in the young 
Platanista which served for comparison. 
The axis has a massive body, and a high neural arch. There is no distinct odontoid 
process, but only a general (though strongly marked) prominence of the anterior surface of 
the body, especially towards its lower margin. On the under surface of this there is a 
large rounded articular facet for the inferior process of the atlas. This is continuous at 
the sides with the anterior articular facets, and would indicate a tolerably free motion 
between the first two bones of the neck. In Platanista this anterior projection of the 
body of the axis is still more strongly marked, forming a process quite comparable with 
the “odontoid” of other Mammalia. In Beluga it is almost wanting. The other pro- 
cesses of this vertebra differ somewhat in detail from those of Platanista. 'The spinous 
process is broad and bifid; the posterior zygapophyses are much less prominent, and their 
surfaces look more backwards. A proper transverse process can scarcely be said to exist. 
There are, however, instead of the single, conical, backward-directed process of Plata- 
nista, slight rudiments of an upper and a lower process, with a groove between them, on 
the hinder surface of the lateral wings of the bone which support the great articular 
facets for the atlas. The posterior epiphysis of the body was not ankylosed. 
description, I must admit the possibility of some of them being lost; but the circumstances under which the 
skeleton was prepared render this, at the least, extremely improbable. When it arrived in this country the 
vertebra were all united by their natural ligaments, Unfortunately they were not counted when in this state. 
