SHARKS AND DOG

- FISHES.— form the group Selachoidei among These Selachians (g.v.). All can be easily the by the firm, round, tapering recognized body with projecting snout and unsymmetrical tail, by the external gill openings, ths rough, sandpaper-like and the strong, sharp, triangular skin, in many rows, the hinder of teeth set ready to replace a worn or which are damaged series in front. All are carnivdevouring other fishes or offal, orous, occasionally man, but a few, like the or Shark, which feeds on seawee ds Basking medusoids, are h e . The and lay their oges in horny ‘purses,’ majority attached to seaweeds, but sometimes such as the Hammer-Head and several, Porbeagle, the ‘Hounds,’ the Piked the Dog-Fish, bring forth living young. are many kinds of Dog- ‘ishes There Sharks, names which indica te no -and groups, but refer rather to size natural to e ential characters; it will than l examples. suffice to mention a few typic a Dog-Fishes proper (Scyllitdae) ars The in all mostly small in size, and occur species of Scyllium are comseas, Two mon, and are sometimes used for food— the Nurse, Bounce, or Larger Spotted Dog-Fish, and Rough or Row Hound or Le er Spotted Dog-Fish, the former reaching a length of 4 ft., tho latter of. 3% i, ft. About the same size is the Picked or Piked Dog-Fish (Acanthi as »yulgaris). Rarer and le welcome are the Blue Shark (Car char i as glaucus), which every summer destroys many nets and fishing-lines; and the_fierce related to the last is the most vicious of all the man-eat i ng, or Great White Shark (Char cha rod on rondelet it), a dreaded inhabitant of all tropical and subtropical seas, sometimes reaching & length of 40 ft. A great contrast is afforded by the Basking Shark (Cetor hin us maximus), which, equally large, is a lazy, inoffensive creature, useful on account of the oil in its liver. One cannot gaen a),—characterized by remarkable tas of the head, at the end of which the eyes are placed