484 



FISHES, 



Ventral fins v.iith one s'jjine and five rays, all heing rudimentary 

 and forming the osseous support ofi a round disk, which is sur- 

 rounded hy a eutaneous fringe. Gill-openings narrow, the gill- 

 menibrancs being attached to the isthmus. 



Carnivorous fishes, living at the bottom of the shores of 

 northern seas. By their ventral disk they are enabled to 

 attach themselves very firmly to rocks. 



Cyclofterus. — Body thick, short, covered with a viscous, 

 tubercular skin. Head large, snout short. Villiform teeth in 

 the jaws, none on the palate. Skeleton soft, Avith but httle earthy 

 matter. 



Three species of " Lump-suckers " are known from the 

 northern temperate and the arctic zones. The common 

 North European and North American species, C. lumpus, is 



Fig. 218. — (.'j'clopterus lumpus. a, Ventral disk. 



known also by the names of " Cock- and Hen- Paddle," 



It 



attains to a length of twenty-four inches, l>ut generally is 

 much smaller. It is difficult to remove it from any object to 

 which it once has attached itself by means of its sucking-disk. 

 Its skin is so thick as to more or less entirely conceal the first 

 dorsal fin ; it is covered with rough tubercles, the larger ones 

 being arranged in four series along each side of the body. 

 In young specimens these tubercles are absent. The arctic 

 species, C. sp)inosus, has large conical plates on the head and 



