MR. W. H. FLOWER ON THE OSTEOLOGY OF THE SPERM-WHALE. 533 
the outer margin of the articular facets. The broad flattened lateral parts of the 
neural arch rise from directly over the upper edge of the articular facets, and converge 
rapidly together to form the anterior surface of the broad rugged mass constituting the 
neural spine. On the right side is a raised flat surface corresponding and fitting to 
that described on the commencement of the arch of the atlas. The opening of the 
neural canal, as seen in this aspect, is a transversely elongated lozenge, with the angles 
rounded off, 85” broad, and 65” high. The inferior margin is very indistinctly marked 
in the middle,—the anterior surface of the axis above the rudiment of the odontoid 
process gradually passing into the flattened floor of the neural canal, which continues to 
rise throughout the cervical region. 
The sides of the mass formed by the conjoined bodies slope gradually downwards 
and inwards, converging towards the middle line, where they meet in a slightly elevated, 
rounded, longitudinal keel, in which all trace of the original separation of these vertebrae 
and even of the first dorsal is entirely lost. 
As in the Toothed Whales generally, the transverse process of the axis consists of a 
single, broad, imperforate plate, springing from the greater part of the side of the body 
of the bone and the lower part of the neural arch, representing, in situation at least, 
the upper and lower processes found in the succeeding vertebre (and in the axis of the 
Whalebone-Whales), coalesced and with the intermediate space filled up. In relation 
to the large size of the body of the bone, these processes may be considered short: 
the condition of the ends, in the Tasmanian specimen, shows that they have not quite 
attained their complete ossification ; but they are only very slightly longer proportionally 
in the completely adult Caithness Whale. They are much compressed from before back- 
wards, and obliquely truncated externally, the nearly straight end looking upwards and 
outwards. In the older specimen more advanced ossification of this apophysis has caused 
the end to approach nearer to a vertical line. 
In most Cetacea the inferior transverse process of the cervical vertebre ( parapophysis, 
Owen), arising from the side of the body, increases in development from the third to 
the sixth, and suddenly becomes obsolete, or nearly so, in the seventh, where the 
articular facet for the head of the first rib appears as it were in its place, situated, 
however, not precisely at the same spot on the side of the vertebre, but rather above 
and posterior to it. In all known genera of Delphinoids the inferior process of the 
sixth vertebra attains a considerable development, most strikingly so in those in which 
the vertebre are free, as Beluga and, especially, Platanista. In Hyperoodon it is very 
conspicuous, although the third, fourth, and fifth show no rudiment of the process. 
In that genus also, at least in one example (Mus. Roy. Coll. Surg. No. 2480 4), con- 
trary to the general rule, a tolerably long inferior process is developed from the body of 
the seventh vertebra, but on the right side only. In the ‘Tasmanian Sperm-Whale there 
is no trace of an inferior transverse process on the smooth sides of the bodies of any of 
the cervical vertebrz as far as that which appears to be the sixth, inclusive. The lower 
VOL. VI.—PART VI. j 3A 
