GAD us. 



331 



and the consequent modification in development is in an intermediate 

 position. The three types will be compared after the frog has been 

 dealt with (see page 358). 



III.— GADUS. 



Phylum - 

 Sub-Phylum 

 Class 

 Order - 



Chordata (p. 402). 

 Vertebrata (p. 405). 

 Pisces (p. 434). 

 Teleostomi (p. 437). 



The haddock (Gadits ceglejinus) is one of the commonest and best 



known of our British fishes. It is described here as a type of the order 



Teleostomi or bony fishes. The haddock is a smaller fish than the cod 



Colour and ^^^ larger than the whiting ; all three belong to the 



Habits large family of Gadidce. It frequents the deeper offshore 



water and is a ground-feeder upon small Crustacea, 



Mollitsca and Amielida. The freshly-caught haddock is of a beautiful 



colour. The ventral surface is a pearly-white which gradates up 



fig- 235.— Lateral View of the Haddock {Gadits ceglefinus) x y^, 



{Ad nat.) 



Lateral Line. 



2nd Dorsal Fin. 



3rd Dorsal Fin. Caudal Fin. 



/ ,. 



" H^£^ 



Uperculuu. {Jru'"^ '2nd Anal Fin. 



Pectoral Fin. p^j^^^ ^^^ J_ | j^^^;^ \^^ ^^^1 pj„^ 

 Fin. Genital Aperture. 



each side into a metallic violet darkest along the dorsal surface. 



Along each side is a thin black line, the lateral Ime^ extending from 



the head backwards to the tail. Just below the anterior part of this 



line there is on each side a black spot of pigment. The eyes are 



_ . silvery and black. The whole body is enclothed in an 



FeatSes investing coat of delicate overlapping cycloid scales, 



developed in the dermis and carrying no spines. The 



skin is extremely slimy, as in the skate. 



At the anterior end of the head is a large gaping mouth armed with 

 upper and lower rows of teeth. Below the chin is a small sensitive 



