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CETACEAN GALLERY. 
feeding, they fill their immense mouth with water containing 
shoals of these small creatures, and then, on their closing the jaws 
and raising the tongue so as to diminish the cavity of the mouth, 
the water streams out through the narrow intervals between the 
hairy fringe of the whalebone-blades, and escapes through the lips, 
leaving the living prey to be swallowed. 
Among other characters by which the Whalebone Whales are 
distinguished from the Toothed Whales, may be mentioned : — The 
external openings of the nostrils are distinct from each other, and 
consist of a pair of longitudinal valvular slits on the top of the 
head ; the two sides of the upper part of the skull are symmetri- 
cally developed; the organ of smell, though small, is formed as in 
other mammals. The branches of the lower jaw are greatly curved 
outwards in the middle, and are loosely connected both to the skull 
behind and to each other in front by fibrous bands. When the 
mouth is open in feeding, they fall outwards, widening the capa- 
cious bag formed by the very dilatable skin of the throat (the 
power of distention of which is aided in many species by a series 
of longitudinal folds), which may be compared to the sac under the 
bill of the pelican. By their rotation upwards and inwards when 
the mouth is closed, they are brought close to the upper jaw. The 
sternum or breast-bone is composed of a single piece, often taking 
the form of a cross, and articulates only with a single pair of ribs. 
There are never any ossified sternal ribs. 
The Whalebone Whales represented in the collection belong to 
five distinct types or genera. 
Balcena (Right Whales). Skin of throat smooth, not furrowed. 
No dorsal fin. Cervical vertebra) united into a single mass. Pec- 
toral limb broad and short, with five fingers. Head very large. 
Baleen very long and narrow, highly elastic and black, as seen in 
the specimens near the window at the further end of the room. 
This genus contains the well-known Greenland Right Whale 
{Balccna mysticetiis) of the Arctic seas, wliich yields whalebone of 
the greatest value and train-oil. It never leaves the ice, and so is 
not an inhabitant of the seas round our islands, but is hunted every 
summer in Baffin^s Bay and the seas round Spitzbergen by ships 
fitted out at Dundee and Peterhead. The Museum at present only 
possesses a skull of this most interesting animal; but a carefully 
