316 



ZOOLOGY 



is built among the plants of the stream, consists of a short 

 cylinder, through the horizontal cavity of which the fish can 

 lie while it deposits its eggs. The male guards the single nest, 



Fig. 296. — Gadus morrhua, the codfish. About one-seventh nat. size. 



After Storer. 



and is polygamous, i.e. fertilizes in the one nest the eggs from 



various females (Figs. 294, 29.5). 



The codfishes, among the most im- 

 portant of food fish, have ventral fins, 

 without spines, and jointed fin-rays, 

 well-developed tail fin, and barbel on 

 chin. Our conunon codfish (Fig. 296) 

 occurs over the whole of the North 

 Atlantic ; but the most important fish- 

 ing localities are the banlvs near New- 

 foundland, especiall}^ Grand Bank. 



The flatfishes are pecuhar among 

 fishes in that they have the habit in the 

 adult stage of lying on one side. In 

 conseciuence the under eye migrates to 

 the upper side, so that both eyes come 

 to lie on the same side of the body. 

 The mouth also tends to become unsym- 



FiG. 2"J7 — OutUne ot one 

 of the flatfishes, seen 

 from the upper side, 

 reduced. From " Cam- 

 bridge Nat. Hist." 



