MR. W. H. FLOWER ON THE OSTEOLOGY OF THE SPERM-WHALE. 335 
As the posterior surface of the body of the cervical vertebre is ankylosed with 
the first dorsal, little can be said of its characters. The centrum, however, is very 
deeply concave, receiving the convex anterior surface of that of the first dorsal; and 
there is a smooth articular facet (posterior zygapophysis) at each side of the neural 
arch. ‘his facet is more vertical (inclining less backwards at the upper end) than 
in other Cetacea. 
Measurements of the conjoined six posterior Cervical Vertebre. 
|Tasmanian, Caithness, | 
| 
| in. | in. 
Eectremo breadth) qa, cegetper oe stsisrs sO MPR REE «oon MOONE «6.0 4 96. 32 | 364 
Bextreamewheight capper tetetete sie s ave aval eaghetmiete #.: kt eNCe 8S @: «cio, oa 222 | 24 
Breadth between outer edges of articular facets for atlas ...... 23 25 
| Breadth of anterior opening of neural canal................-- To oO 
Height of anterior opening of neural canal .................- 65 | fi 
Height of body of bone below this ..............e0eeeeeees | 92 103 
| Antero-posterior length of superior surface (floor of neural canal). 4 | 
Antero-posterior length of inferior surface ..............00++ 5t = 
Antero-posterior length of lateral surface................005- 9 113 
Breadth of posterior surface of body of seventh cervical vertebra.) 174 15 
Height of posterior surface of body of seventh cervical vertebra . . 103? 12} 
The Dorsal Vertebre (Pls. LVIII. and LIX.) are eleven in number. The first ten 
support well-developed ribs; the eleventh, which in many of its characters resembles 
a lumbar vertebra, has only a rudimentary pair of ribs attached to the extremity 
of the transverse processes. The first dorsal is ankylosed by the middle part of its 
centrum (at all events at the upper and lower margins near the middle line, where no 
trace of a suture remains) to the hinder part of the conjoined six posterior cer- 
vical vertebree. The lateral parts of the centrum are free, as also is the whole of the 
neural arch. 
The body of the first is by very far the shortest in the antero-posterior direction; the 
second is nearly twice as long; and they continue to increase gradually and progressively 
throughout the series, as will be seen by the table of measurements. The body of the 
first is extremely concaye on its posterior aspect, the middle part being 3” deeper than 
the sides. The second is convex in front, and concave behind to a less degree. In the 
succeeding vertebre the anterior and posterior surfaces are nearly flat and parallel. 
The bodies, at first very broad in proportion to their height, rapidly become narrower ; 
in the fourth the breadth is already less than the height ; the sixth, seventh, and eighth 
are the narrowest; after these there is a slight increase of width. 
The neural canal in the first two vertebre is triangular, but rapidly assumes a trans- _ , 
versely oval form, and gradually diminishes in both height and breadth, so much more, 
however, in the last dimension that in the tenth vertebra the long diameter of the oval 
is vertical ; in the eleventh the lateral contraction is still more marked. 
342 
