DISTINGUISHING CHARACTERS OF BRITISH CETACEA. 5 
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. 
Balenoptera musculus (Linn.). Common Rorqual, Finner, or 
Razor-back.—Averages from 60 to 70 feet in length, has 61 or 62 
vertebra 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 Balenoid 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. 
Balenoptera Sibbaldii (Gray). - Sibbald’s Rorqual.—Averages 
from 60 to 80 feet in length; has 64 vertebre 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. 
Balenoptera laticeps, Gray. Rudolphi’s Rorqual.— Averages 
from 30 to 40 feet in length; has 58 vertebra 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 Balenoptera bodps. 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. 
Balenoptera rostrata(Fabricius). Lesser Rorqual.—The smallest 
species of the genus, averaging from 25 to 30 feet in length, and 
having 48 vertebre 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 
