Page:The Zoologist, 3rd series, vol 2 (1878).djvu/33

Rh commonest of all the Cetacea which visit the coasts of Great Britain.

In some respects not unlike Phoccena, but distinguished at once by its head, which, instead of being rounded, has a prolonged beak, and double the number of teeth.

Delphinus delphis, Linnaeus. Common Dolphin.—Exceeds the Porpoise in size, attaining a length of from 6 to 8 feet. The vertebra? vary from 70 to 75 in number. The jaws are long and powerful, the lips thin and compressed. The teeth, of which there are from 40 to 50 on each side of bolh jaws, are acute and slightly curved, and those in the upper jaw fit very regularly between those in the lower. The colour is black, gradually shaded through grey on the sides to pure white beneath. The Common Dolphin appears to have a much more extensive range than the Porpoise, being found in the more temperate regions on both sides of the North Atlantic and in the Mediterranean. It is by no means uncommon off our own coasts, and is not unfrequently captured in fishermen's nets.

Delphinus tursio, Fabricius. Bottle-nosed Dolphin.—Much larger than the common species, averaging from 8 to 12 feet, but with not much more than half the number of vertebræ (41) and half the number of teeth (20 to 25 on each side of both jaws). The beak is shorter than in the last-named species, as also are the dorsal fin and flippers. The name "Bottle-nosed" has been bestowed from the shape of the skull.

Delphinus acutus, Gray. White-sided Dolphin.—About equal in size to the Common Dolphin, averaging from 6 to 8 feet in length, but with a larger number of vertebra? (80 or 82) and a smaller number of teeth (28 to 36 in each side of both jaws). It may be distinguished at a glance by its colour. It is black above and white beneath, like its congeners, but the flanks are yellow or brownish grey, with an oval white patch in the centre, which gives it a marked appearance. Two or three specimens only of this rare species have been captured in the Orkneys.

Delphinus albirostris, Gray. White-beaked Dolphin.—Averages 7 to 9 feet in length, with 88 or 90 vertebræ and 15 pairs of ribs. The beak elongated and gradually tapering to the extremity. The