578 



CHORD AT A. 



(Lota,* burbot), all are marine. The GADID^E, with Gadus,* in- 

 cluding the cod and haddock, and the 

 PLEURONECTID^E, with Hippoglossus,* 

 the halibut and other genera, the floun- 

 ders,, turbot, and sole, make this the 

 most important group of marine fishes. 

 The Pleuronectidae, from their asym- 

 metry, need a word. The young are 

 perfectly symmetrical, but the animals 

 turn on one side, the lower becoming 

 white. The eye of this side gradually 

 works over to the upper side, twisting 

 the bones of the skull in its progress. 



Order V. Lophobranchii. 

 A small group of marine species, 

 having in common gills composed of 

 small rounded tufts, the body covered 

 with a segmented armor of bony plates 

 and peculiar breeding habits, the male 

 carrying the eggs and young in a brood 

 pouch. The sea horses, Hippocampus,* 

 with their horse-like heads, and the 



FIG. GOT. -Hippocampus hepta- slender pipe fishes, Syngnathus,* belong 



gon 

 Goc 



us,* sea horse. (After 

 code.) 



here. 



Order VI. Plectognathi. 



A small group of peculiar compact fishes, in which the bones 

 in each jaw are coossified, the ventral fins reduced or absent. In 

 the trunk fishes, Ostracodermi, the body is enclosed in a firm angu- 



FIG. 608. Chilomycterus geometricus,* swell fish. (After Goode.) 



lar box of bony plates. The G-ymnodonta, or swell fishes (fig. 608), 

 have the power of inflating the body to spherical sacs. The flesh 

 is poisonous. 



