BARRACUDAS, REMORAS AND OTHERS 183 



SUN-FISHES OR HEAD-FISHES. 



(Family Molid.e ; Genus Mola.) PI. V b ; Fig. 58. 



The Sun-fishes, with which we conclude our survey of the 

 giant Bony fishes, belong to another Order, the Plectognathi, 

 the members of which have been evolved from Perch-like 

 ancestors. This is a large and varied group of fishes, and 

 includes such diverse types as the File-fishes, Leather-jackets, 

 Trigger-fishes, Trunk-fishes, Puffers, Globe-fishes, Porcupine- 

 fishes and Sun-fishes. Only the last-named grow to any size, 

 and may be defined as follows : 



The body is deep, oval in shape, and covered with a thick, 

 rough, leathery skin. The snout projects a little above the 

 small mouth, in which the teeth are fused together to form a 

 single, bony, sharp-edged plate or " beak " in each jaw. The 

 dorsal and anal firis are very large and high, and are placed 

 opposite to each other ; behind them the body ends abruptly 

 without any decrease in depth, and is margined by a low tail- 

 fin, which may be evenly rounded, wavy in outline, or drawn 

 out into a point in the middle. The pectoral fins are short 

 and rounded, and are placed just behind the small gill-openings. 

 There are no pelvic fins. There is no air-bladder. The 

 coloration is uniformly grey, olive-brown, or nearly black, 

 with silvery reflections on the sides ; young individuals are 

 dark above, with some more or less conspicuous round dark 

 spots on the hinder part of the body, and white beneath ; 

 very young individuals are silvery on the belly. 



Grow to a length of 8 to 10 feet and a weight of more than 

 a ton. 



Two species are recognized, and some authorities place 

 these in separate genera. Both have a world -wide distribution 

 in tropical and temperate seas. The Common, Round-tailed, 

 Short or Ocean Sun-fish (M. mola) has the hinder part of the 

 body rounded or wavy in outline ; the Tailed or Pointed- 

 tailed Sun-fish (M. lanceolata) has the hind end of the body 

 more or less pointed in the middle. The latter is a very rare 



