CHAPTER LIII 



ORDER OF SOLID-JAW FISHES 

 PLECTOGNATHI 



THE characters on which the members of this Order 

 have been brought together are, for the general reader, 

 rather obscure. Thcv are strictly anatomical, and relate to 

 the manner in which the teeth and bones of the jaw are 

 grown together and solidified. On the whole, it will be 

 'about as easy to become acquainted with the various groups 

 of fishes composing the Order as to learn fully and correctly 

 the precise anatomical characters which are common to all. 



This Order contains some very odd and picturesque 

 forms; and, fortunately for the student, good examples of 

 them are fairly common along the Atlantic coast. 



The Trigger-Fish, 1 or Filefish, is a very good species 

 to represent this entire group. It derives one of its nanus 

 from the large, movable spine of solid bone (a fin-ray of the 

 front dorsal fin), which stands upon the foremost point of 

 its back, with a smaller trigger behind it, like that upon an 

 old-fashioned hair-trigger rifle. The large spine can be set 

 quite rigidly by a neat interlocking device supplied by the 

 second spine. 



This fish is a thin-bodied creature, and its skin has the 



1 Ba-lis'tes ca^pris'cus. 

 25 1 



