CARCHAKIAS. 91 



Blue Shark, — Carcharias Glaucus. Blue 

 sharks seem to be universally distributed over the 

 world : navigators have never penetrated a sea in 

 which they were not seen. They have a some- 

 what slender body, of a deep slate blue, on the 

 back and sides, but the color is considerably light- 

 er under the pectoral fins and abdomen. They 

 have, beside, a long, pointed snout, a bilobed tail, 

 of which the lower one is the longest. Usually, 

 they average from seven to fourteen feet in length. 

 Vessels are followed by this shark, sometimes, 

 hundreds of leagues, without cessation. Seamen af- 

 firm that it is exceedingly greedy of human flesh. 

 This opinion has arisen, probably, from the circum- 

 stance that the species is so widely diffused, that 

 a body is scarcely lowered into the water, in any 

 latitude, before some of these voracious Bedouins 

 of the sea make their appearance. 



iElian assures us that when their young are in 

 danger, they rush down the throat of the mother 

 for security. The young of this species are hatch- 

 ed from the egv, in the coiled oviducts of the fe- 

 male, and therefore, when expelled, are not only 

 alive, but exhibit, instantly, their natural character, 

 by seizing with their tiny mandibles, anything 

 that comes in their way. 



To each young one, is suspended, by the um- 

 bilical cord, a sack, in which is enclosed the yolk 



