93 
and Rhino ., is thick, like those of the sharks ; in RQQM XL 
others, as the Ray (jR aia), it is slender, and 
often armed by small spines. In the Sting Ray 
( Trygon ), it is very long and slender, and armed 
with a long bony spine, serrated on both its 
edges. 
The Sea Eagles ( Myliobates ) have a long 
tail like the Sting Rays, but their pectoral 
fins are very broad, so that they in some measure 
resemble a bird of prey with its wings extended. 
The Cephaloptera are very like the Sea 
Eagles, but their head is truncated in front, and 
the front edge of the pectoral fin is expanded 
like two horns. 
The Electric Ray ( Torpedo ) is peculiar for 
its body resembling a violin or guitar in shape. 
The mouth of most of the Rays is armed with 
tubercular teeth placed in angular rows like a 
pavement. The teeth of the Sea Eagle are 
large flat plates, formed of several transverse 
series of flat pieces. The teeth and caudal 
spines of these fishes are often found in a fossil 
state; the former being called palates. 
The last family of fishes is that of the Lampreys 
( Petromyzidce ). Their skeleton is the most 
imperfect of all the vertebrated animals. Their 
body is long, slender, cylindrical, ending in a 
circular mouth, and destitute of any pectoral or 
ventral fins. The true Lamprey has seven 
branchial openings, whence they are called 
Seven 
