314 
CARTILAGINET.— RAIAD^. 
lating action of the pectorals. The great size, 
however, of these fins indicates that, on occasion, 
they can shoot along with great swiftness. They 
are very voracious, devouring any fishes that they 
can master, as well as Crustacea^ and shelled 
mollusca ; the strong fiat teeth, with which their 
jaws are paved, are able to crush to powder the 
stoutest shells of lobsters and crabs. Some of 
the species, especially those of tropical seas, 
grow to an immense size, and are ferocious in 
proportion to their dimensions. Specimens of 
the Cephaloptera have been seen twenty five feet 
in length, and thirty in breadth; and one was 
captured a few years ago at Barbadoes, which 
weighed three thousand five hundred pounds. 
Col. Hamilton Smith saw one of these monsters 
seize and carry down a man who was swimming 
in the sea near Trinidad. 
About a hundred and thirty species are known 
to belong to this Family, all of which are ma- 
rine. They are found in all seas, and the British 
coasts possess no fewer than sixteen. The fol- 
lowing groups constitute the Sub-families of 
the Rays. 
1. Rhinohatina. The Shark -rays. This form 
may be considered as almost equally partaking of 
the characters of the two Families whose names 
it conjointly bears. The body is much longer 
than broad, the tail is thick, and tapers gradually 
from the trunk ; the snout is short and elongated. 
They mostly inhabit the Indian Ocean and the 
Red Sea. 
2. Torpedinina. The Electric Rays. Here 
the tail is short and fleshy, but distinctly sepa- 
rated from the disk of the body, which is nearly 
