BALA NIDA 241 
always, free, while in young individuals the axis vertebra may 
likewise be separate. 
Neobalena..—Head about one-fourth the total length. Skin of 
the throat not plicated. A small falcate dorsal fin. Vertebre, 
C7,D17,L3,C16=43 The cervical vertebre are united. The 
manus small, narrow, and tetradactylous, wanting the pollex. The 
ribs remarkably expanded and flattened. The scapula very low 
and broad, with completely developed acromion and coracoid pro- 
cesses. Tympanic approximating to that of Balena, but with certain 
very characteristic peculiarities of shape. Baleen very long, slender, 
elastic, and white. A single species, at present very rare, VV. mar- 
ginata, from the Australian and New Zealand seas is the smallest 
of the Whalebone Whales, being not more than 20 feet in length. 
Rhachianectes.2—This combines the small head, elongated form, 
and narrow pectoral fin of Balcenoptera with the smooth skin of the 
throat and absence of the dorsal fin of Balena. The baleen is the 
shortest and coarsest of any of the group. Its osteology is im- 
perfectly known. One species, 2. glaucus, the Gray Whale of the 
North Pacific. 
Mlegaptera.2—Head of moderate size. Baleen plates short and 
broad. Vertebre, C 7, D 14, L 11, C 21=53. Cervical vertebrae 
free. Scapula with acromion and coracoid process absent or rudi- 
mentary. Skin of throat plicated. Dorsal fin low. Pectoral limb 
tetradactylous, very long and narrow, attaining about one-fourth of 
the length of the entire animal, the metacarpus and phalanges 
being greatly developed, and the latter very numerous. Tympanic 
still more inflated than in Balenoptera, with the involuted portion 
more distinctly pyriform, the Eustachian part of the aperture well 
defined, and two well-marked longitudinal ridges on the lower 
surface of adult specimens. 
The Whale commonly called “ Humpback” (Megaptera boops) by 
whalers, perhaps on account of the low hump-like form of the 
dorsal fin, is very distinctly characterised from all others of the 
group, especially by the immense length of the pectoral fins or 
flippers, which are indented or scalloped along their margins, and 
are, except at their base, of a white colour, nearly all the rest of 
the body being black. The baleen plates are. of a deep black 
colour. Though common in the North Atlantic between Norway 
and Greenland, this Whale does not frequently appear on the coasts 
of the British Isles. One came ashore at Newcastle in 1839; 
another, a young one, was taken in the estuary of the Dee in 1863, 
and its skeleton is preserved in the Liverpool museum; and a 
nearly full-grown animal was captured in the mouth of the Tay in 
1 Gray, Suppl. Cat. Seals and Whales in Brit. Mus. p. 39 (1871). 
2 Cope, Proc. Ac. Nat. Sei. Philad. 1869, p. 15. 
2 Gray, Zoology of Ercbus and Terror, p. 16 (1846). 
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