146 



ZOOLOGY 



It grows to the length of twelve feet, and is one of the 

 most rapacious and formidable of sea-monsters. Among 

 the largest sharks are the species of Carcharias (Fig. 187) 

 One species frequents the Ganges, occurring sixty leagues 

 from the sea. 



Of the rays and skates, the saw-fish (Pristis antiquorum) 

 approximates most to the sharks. Its snout is prolonged 

 into a long, flat, bony blade, armed on each side with large 



teeth (Fig. 188). The common saw- 

 fish inhabits the Mediterranean Sea 

 and the Gulf of Mexico; it is vivipa- 

 rous (Caton). Pristis Perroteli lives 

 in the Senegal River. 



The genuine skates or rays have 

 the body broad and flat and rhom- 

 boidal, owing to the great extension 

 of the thick pectoral fins. They 

 swim close to the bottom, feeding 

 upon shell-fish, crabs, etc., crushing 

 them with their powerful flattened 

 teeth. The smallest and most com- 

 mon skate of our northeastern Atlan- 

 tic coast is Raja erinacea. It is one 

 half of a metre (twenty inches) in 

 length, and the males are smaller 

 than the females. The largest species 

 is the barndoor skate, Raja Icevis, 

 which is over a metre (forty-two 

 inches) long. Raja eglanteria (Fig. 

 189) ranges from Cape Cod to the 

 Caribbean Sea. The smaller figures 

 in Fig. 189 represent respectively the 

 ||P||| mouth and gill-slits, and the jaws of 



Fig. 188.-Beak of Saw-fish, MyUobcitis fmnenvillli. 



XTSSiFSSSS^ In the torpedo the body is some- 



lateral teeth. what ovul and roun ded. Fig. 190 



represents Torpedo marmoratus of the Mediterranean Sea. 



