5i6 PISCES SUB-CLASS IV.ELASMOBRANCHIL 



nally by the long and nearly cylindrical body, the powerful rudder-like tail, 

 the presence of an anal tin, the moderate dimensions of the pectorals, and 

 the small size or absence of the spiracle. In consequence of the divergence 

 of the two branches of the jaws, the teeth form oblique rows, and at 

 least the teeth in the front of the jaws are sharp-pointed, their general 

 form being a much flattened cone, with or without lateral cusps at the 

 base. 



In the family typified by the formidable blue shark there are no spines to 

 the fins ; the first dorsal fin is placed immediately over the space separating 

 the pelvics from the pectorals, the teeth have hollow crowns, 

 Family and are generally sharp-pointed, the mouth is inferior, the 

 Carchariidce. skin is of the shagreen type, and the eyes are furnished with 

 a nictitating membrane, which fulfils the function of an eye- 

 lid. The limits of our space forbid giving the distinctive features of the 

 various genera included in this family. The blue shark (Carcharias glaucus) 



is the most familiar 

 representative of the 

 type genus, while the 

 strange-looking ham- 

 mer-headed sharks 

 form another genus 

 (Sphyrna), distin- 

 guished from all 

 other fish by the 



Fig. 36. BLUE SHARK, peculiar flattening 



and lateral expan- 

 sion of the muzzle into a pair of projecting lobes, each bearing an eye at its 

 apex. These sharks grow to a length of about fifteen feet, and are fairly 

 abundant in the warmer seas. The genus Galeus, in which the head is of 

 normal form, includes small sharks, represented in British waters by the 

 tope (G. canis). Other small British sharks known as hounds (Mustelus) 

 differ externally by the more blunted form of the muzzle. Unlike the species 

 of Carcharias, these sharks haunt the bottom of shallow seas, where they 

 feed on shell-fish, crabs, etc. They produce living young. Stories of the 

 ferocity of the various kinds of large carnivorous sharks are so numerous that 

 it is difficult to make a selection. The following anecdote by the well-known 

 writer, Mrs. Bowdich, is, however, of special interest, as illustrating the 

 indifference to the near presence of these terrible monsters which seems to 

 become habitual to the natives of many of the warmer coasts. " Sharks 

 abounded at Cape Coast," writes this lady, "and one day, as I stood at a 

 window commanding a view of the sea, I saw some of the inhabitants of the 

 town bathing, and the sharks hastening to seize upon them they being 

 visible from always swimming with part of their dorsal fin out of water. I 

 sent to warn the men of their danger, and all came ashore except one, who 

 laughed at the caution of his companions. A huge shark was rapidly ap- 

 proaching, and I sent my servant again, and this time armed with half a 

 bottle of rum to bribe the man to save himself. It was too late. The mur- 

 derous creature had seized him, and the water. around was dyed with his 

 blood. A canoe was despatched to bring him ashore, but a wave threw him 

 on to the beach, and it was found that the shark had taken the thigh-bone 

 completely out of the socket. The man, of course, expired in a few minutes. 

 Accidents were often happening, and always fatal, and yet the negroes, who 



