respects, in having a more slender body in proportion to the length, very short flippers with their edges even, a smaller and more pointed head, and a shorter tail.
Balænoptera musculus (Linn.). Common Rorqual, Finner, or Razor-back.—Averages from 60 to 70 feet in length, has 61 or 62 vertebras and 15 pairs of ribs. In colour it is black above, shaded to a brilliant white below; flippers black; baleen slate-colour, streaked with paler shades. It inhabits the more temperate northern seas, with a much more southern range than the Greenland Right Whale, and is the only Balænoid Whale which is found in the Mediterranean. It has been met with on all parts of the British coast. The name "Rorqual" is derived from the Norse "Rorq-val," signifying a whale with pleats or folds in the skin.
Balænoptera Sibbaldii (Gray). Sibbald's Rorqual.—Averages from 60 to 80 feet in length; has 64 vertebrae and 16 pairs of ribs. The head is broad; the flippers long and broad; the dorsal fin very small. In colour it is black above, grey beneath, with whitish spots and markings; the flippers are black above and white below; the baleen uniform deep black. It is frequently met with between 63° 40' and 66° 20' N. lat., and is the commonest Fin Whale about Iceland, where it is found chiefly in summer. Specimens have been procured in Hamna Voe, Shetland, in the Firth of Forth, and elsewhere on the coast of Scotland.
Balænoptera laticeps, Gray. Rudolphi's Rorqual.—Averages from 30 to 40 feet in length; has 58 vertebrae and 14 pairs of ribs. The head is broad; the dorsal fin very small; the flippers short. In colour it is black above, white below; flippers the same; the baleen black. A specimen believed to be of this species was stranded at Charmouth, Dorsetshire, in 1840, and was described by the late Mr. Yarrell in the 'Proceedings of the Zoological Society' for that year, under the name Balænoptera boöps. Another was cast ashore on the Island of Islay in 1866, the skull of which is preserved in the Museum of the University of Cambridge.
Balænoptera rostrata (Fabricius). Lesser Rorqual.—The smallest species of the genus, averaging from 25 to 30 feet in length, and having 48 vertebrae and 11 pairs of ribs. The dorsal fin is much more developed than in the last-named species, and, although the general colour is the same, the flipper in this species is black, with a broad white band across it, which seems to be a constant peculiarity, and affords a good mark of distinction. It inhabits the
