LECTURE VIII. 
73 
its general habits. It sometimes is seen to swim 
with a considerable degree of swiftness^ but is 
more commonly found adhering by the mouth to 
some large stone or other substance, to which it 
clings so powerfully as to tequire a great degree 
of force to separate it. As an article of food the 
Lamprey has long been celebrated. Its usual 
colour is a dull yellowish- white, clouded with 
brown or olive- colon red variegations. All the 
rest of the genus are of much smaller size, but in 
shape and way of living resemble the great Lam- 
prey, except that they are confined to rivers. 
The next genus of the Cartilaginous Fishes 
consists of the Ray or Skate tribe, and is charac- 
terized by a flattish body, in some of a lozenge- 
shape, in others rounded, and in all furnished with 
a lengthened tail ; the mouth is placed beneath 
the head, and is furnished with very numerous 
small teeth generally covering the lips or edges of 
the mouth ; and on each side the neck beneath, 
are placed five large transverse slits or openings 
leading to the gills. The common Skate furnishes 
a good example of this genus, and is the Raja 
Batis of Linnaeus. It often grows to a vast size. 
