6 PROFESSOR FLOWER ON RISSO’S DOLPHIN. 
inches. 
Length of inferior surface of conjoined bodies. . . . . . . . 24 
Length of conjoined arches» 2 0 - 2s ee eee so OD 
Height from inferior surface of atlas to apex of conjoined spinous 
processes . . ek i: sit RE 2p ae e SP ord: 
Breadth of detisnldr sur sfbieies of dius Ee cogs ct | cad Lae ol 
Breadth between tips of transverse processes of atlas. . . . . . 77 
Breadth between tips of transverse processes of axis. . . eles 
Breadth between tips of transverse processes of seventh cantaliea . o2 
Greatest breadth of spinal canal (inside arch of atlas) . . . . . 20 
Height of spinal canal at the same place . . . . . - . . . 14 
The thoracic vertebre are twelve in number. ‘The body of the first is but 0-6 of an 
inch in length; they gradually increase from this to the fifth; but the remainder are 
very nearly equal, viz. 1:7 inch in length, and present no marked differences in breadth 
and height. Articular surfaces for the heads of the ribs are developed on the hinder 
edge of the base of the pedicle of the arch of the first five; and on the sixth there is a 
rough tubercle in the corresponding position. The spine of the first is very small and 
directed forwards; that of the second is equally low, but broader in the antero-posterior 
direction; that of the third is long and pointed, and sloping much backwards; the 
remainder increase gradually in length to the last, and become more upright in position ; 
beyond the sixth they have a slight forward curve. ‘The transverse processes arise in the 
anterior vertebre high up on the sides of the arch; but, as in other true Dolphins, their 
position is gradually lowered until, before the termination of the thoracic region, they 
are transferred to the bodies of the vertebra. In the first seven vertebra they are of 
nearly equal length, but from the eighth to the twelfth they gradually increase. ‘They 
all have articular surfaces at their extremities for the heads of the ribs, at first oval 
from above downwards, but gradually becoming elongated in the other direction. In 
the twelfth the surface is convex and very slightly marked. Zygapophyses are deve- 
loped only as far as the articulation between the sixth and seventh. The metapophysial 
tubercles are slightly indicated on the third, near the outer end of the anterior edge of 
the transverse process; on the sixth and seventh they are prominent, conical, and close 
to the base of the process; on the eighth they become less marked, and begin to rise 
on the side of the arch; and they no longer exist as distinct processes on the eleventh, 
and thenceforth are only indicated by a slight bulging forwards of the anterior edge of 
the upper part of the arch, and do not reappear, as is usually the case, in the lumbar or 
caudal region’. 
The bodies of all the lumbar vertebrae are very nearly equal in length, viz. 1:4 inch. 
‘ The metapophyses of the posterior thoracic region are much better developed in the skeleton of the 
“Grampus rissoanus,” figured by Van Beneden and Gervais (op. cit. pl. 54. fig. 1), than in the present 
specimen. 
