CHAPTER XLIX 



THE 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. They are strictly 

 anatomical, and relate to the manner in which 

 the teeth and bones of the jaw are grown to- 

 gether, 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 ana- 

 tomical characters which are common to all. 



This Order contains some very odd and pict- 

 uresque forms; and, fortunately for the student, 

 good examples of them are fairly common along 

 the Atlantic coast. 



The Trigger-Fish,' or File-Fish, is a very 

 good species to represent this entire group. It 

 derives one of its names 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 toughness, the rigidity and even the 

 external appearance of stamped leather, with the 

 roughness of fine sand-paper. It is a fine fish 

 for the first efforts of the amateur taxidermist, 

 for it has ingrowing scales that cannot possibly 

 come off, and its colors are equally fast. 



All the Trigger-Fishes are habitants of tropical 

 and subtropical waters, and feed chiefly upon 

 small shell-fishes (moUusks) which their strong 

 jaws and teeth enable them to masticate success- 

 fully. Some of them, like the Orange File-Fish, 

 are brilliantly colored. In the tropics they are 

 considered edible, but the few that exist along 

 our Atlantic coast are not ranked as food fishes. 

 The species shown in the illustration is the one 



^ Ba-lis'tes ca-pris'cus. See figure on page 374. 



most widely known along our Gulf coast, and 

 also the Atlantic coast up to the mouth of the 

 Potomac. In the Bahamas and the Bermudas, 

 the skins of Trigger-Fishes are extensively used 

 by carpenters in place of sand-paper for smooth- 

 ing the surface of wood previous to polishing. 



The Box-Fish, or Trunli-Fish," is one of the 

 curiosities of the tropic seas, and of curio-shops 

 generally. Its skin is a rigid, triangular box, 

 shaped in cross-section like an isosceles triangle, 

 and consists of large hexagonal plates of thin 

 bone, joined firmly together by the regular 

 integument. 



Of these fishes we have four species on our 

 Atlantic and Gulf coasts, and one off California. 

 According to Dr. G. Brown Goode, all the species 

 of Box-Fishes were so thoroughly and correctly 

 studied by the fathers of natural history two 

 hundred years ago, that their classification of 

 the group has stood the test of time, and come 

 down even into these troublous times unchanged 

 and unimproved. 



The Bellows-Fish,' or Rabbit-Fish, is pos- 

 sessed of many local names, such as Globe, 

 Bottle, Blower, and even Egg Fish. When 

 taken from the water, and scratched smartly on 

 the abdomen against the grain of the small spines 

 which cover that region, it begins to pump air 

 into its interior, the skin expands like india-rub- 

 ber, and in a moment it assumes balloon-like 

 proportions. If the fish is then thrown into the 

 water, it floats belly upward for a moment, then 

 suddenly the air is expelled, the fish collapses, 

 instantly turns right side up, and disappears. 



This species ranges from Cape Cod to the 

 Gulf of Mexico, and may be looked for with con- 

 fidence in the pound-nets at nearly all our sea- 

 side resorts. 



' Os-trac'i-on quad-ri-cor'nis. See illustration on 

 page 374. 



^ Lag-o-ceph'a-lus lae-vi-ga'lus. 



410 



