40 MARVELS OF FISH LIFE 
rasped off the skin, and for a fortnight after, when I 
dipped my arm in sea-water, I was reminded of that 
fish ! 
In the illustrations of the dog-fish shown, the shape 
and general character of the shark family are well 
illustrated. Note the position of the mouth, the long 
slender body, so well adapted for moving rapidly through 
the water, and the powerful tail, of which the upper lobe 
is much larger than the lower. 
I have already referred to the manner in which the 
female dog-fish attaches her eggs to the seaweed. One 
of the illustrations shows her swimming round a rock. 
This fish deposited an egg a few hours after the photo- 
graph was taken. 
Of skates and rays we have several kinds, but the 
common skate and the thornback ray are those usually 
met with. These fish pass most of their time near the 
bottom, swimming about with an undulating movement 
of the large wing-like fins, one on each side of their 
flattened bodies. 
Their diet consists mainly of crabs, oysters, whelks, 
mussels, small fish and the young of the plaice and sole. 
Not infrequently herrings and other surface-swimming 
fishes have been found inside the stomachs of larger 
rays, and because of this it has been stated that rays 
sometimes feed near the surface. This is very unlikely, 
for I am sure the clumsy ray could only catch the 
herring when that fish was unaware of its presence. 
The probable explanation is that occasionally herring 
