Page:The Zoologist, 1st series, vol 4 (1846).djvu/302

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1468
Cetacea.

especially towards their extremities. The seven first two-headed ribs are joined to the sternum, which is sub- cartilaginous, and the three others or false ribs have the apex free. The sternum, which is not yet ossified in all its parts, is formed of seven distinct bones, the superior one of which is the largest, it is truncate superiorly, and forked posteriorly ; the following sternal bones go on gradually de- creasing in size, and have a square shape with a rounded notch on their anterior and posterior margins. On the inferior surface of the first sternal bone are two rounded depressions.

The eight first costal vertebrae have no lateral processes, but the two last are furnished with them.

The eleven lumbar vertebræ have the same shape as the two last costal ones, their lateral processes are wide, long, and directed for- wards.

The sacral vertebræ and six first caudal vertebræ have both supe- rior or spinal and inferior processes, the seventh and eighth caudal, only spinal ones, and the remainder have no processes of any kind, and are more or less globular. These last go on diminishing gradu- ally in size until the terminal one, which is smaller than a pigeon's egg. The inferior process of the sacral vertebrae is angularly elbowed. The seventh caudal has a small rudimentary inferior process placed on the inferior posterior margin of the vertebrae.

Limbs, &c. Metacarpus wanting or cartilaginous. Scapular ra- ther small, its coracoid process is double the size of the acromion, and slightly curved : humerus shorter than radius : radius and cubitus tubercular, and very approximating : bones of carpus placed in two rows, there are six of them, of which the two medial are the largest : upper finger formed of two phalanges, second of four, third of four, fourth of five, and fifth of one phalanx.

Hyoid apparatus formed of five bones, of which the middle one is pentagonal, and the others depressed and lengthened, two of them being double the size of the others. Two small ischionian bones ex- isted suspended in the flesh, but they had been lost.

Dimensions of Skeleton.

ft. in. line.
Total length of head 2 0 0
Apex of inferior maxilla to auditory canal 0 18 0
Crest to the atlas 0 5 5