DISTINGUISHING CHARACTERS OF BRITICH CETACEA. t 
the under jaw are rudimentary and concealed by the gum. The 
dorsal fin is small and the flippers short and rounded. 
Hyperoodon rostratus (Chemnitz). Common Beaked Whale, or 
Bottle-head. Attains a length of from 20 to 25 feet. The beak 
is depressed and pointed, with a single blow-hole, crescentic in 
shape, concave in front. The maxillary crests are narrow, widely 
separated, and not higher than the occipital portion of the skull. 
The general colour is black above, shaded to grey beneath. This 
whale is a native of the North Atlantic, and in autumn frequently 
comes into British waters, specimens being captured nearly every 
year on some parts of our coast. 
Hyperogdon latifrons, Gray. Broad-fronted Beaked Whale.— 
Attains a length of 25 to 30 feet. Differs from the last-named 
chiefly in the shape of the skull; the bony crests on the maxillaries 
are much thickened and flattened above so as almost to touch one 
another, and rise above the occipital portion of the skull. Nothing 
is yet known of the external appearance of this whale, which has 
been described only from its remains, portions of which have 
been found in Orkney, the Firth of Forth, and Morecambe Bay, 
Lancashire. 
Genus Ziphius, Cuvier. 
Characterized by the peculiar conformation of the skull. The 
rostrum is triangular in shape, at the base of which is a deep 
hollow into which the nares open. There are two teeth in front 
of the lower jaw, conical in shape, and of moderate size. 
Ziphius cavirostris, Cuvier. Cuvier’s Whale.—Although appa- 
rently not uncommon in the Mediterranean, is only known to have 
occurred once in British waters, a specimen having been taken in 
Hamna Voe, Shetland, in 1870, as recorded by Professor Turner, 
of Edinburgh.* It attains a length of about .... feet, and has 
... verlebre and .... pairs of ribs. Its colour is said to be steel- 
gray, with irregular white streaks. 
Genus Mesoplodon, Gervais. 
Distinguished from the last-named genus by the form of the skull, 
which has no hollow at the base of the rostrum (the latter being 
very slender), the nares opening directly on the surface. ‘The 
teeth, two in number, which in Ziphius are situated in front 
of the lower jaw, are in this genus placed one on each side of the 
* Trans. Roy. Soc. Edinb., 1872. 
