Page:The Zoologist, 3rd series, vol 2 (1878).djvu/35

Rh should we omit to indicate as special sources of information the "Recent Memoirs of the Cetacea," edited by Professor Flower, and published by the Ray Society, and Professor Van Beneden's 'Osteographie des Cétacés;' while the excellent chapters devoted to British Whales and Dolphins in the second edition of Bell's 'History of British Quadrupeds' afford an amount of information not elsewhere to be obtained in so concise a form.

 

The Ziphioid Whales, to which group the present species belongs, occupy an intermediate position between the Cachelots and the Porpoises and Dolphins, and are distinguished from other toothed whales by many important structural differences.

"In the upper jaw there are no functional teeth, which are only occasionally represented by rudiments which never cut the gums, while those of the lower jaw are reduced to either one or two pairs, which are often greatly developed, but sometimes remain almost rudimentary. The snout is produced into a more or less distinctly marked ' beak,' the flippers are short and rounded, and the dorsal fin placed very far back. The blow-hole is crescentic, and two diverging furrows in the skin of the throat assume the form of the letter V with its angle directed forward."

Four genera are recognized by Professor Flower, in his memoir on this group of whales, of which the first and best marked is that now under notice, Hyperoodon.

This genus is characterized by its rounded forehead, distinct beak, and comparatively small mouth, and especially by the presence of two bony crests on the upper surface of the maxillary bones of the skull, which rise nearly as high as the occipital portion.

In the present species these raised crests are sharp-edged above, and separated by a considerable interval. In an allied species, Hyperoodon latifrons (Gray), they are much thickened 