THE STICKLEBACKS. 201 



the Bull- Knob of Derbyshire, the Cull of Gloucestershire, the 

 Codpole of Bucks and Berks, the Nozzle-Head of Hants, 

 Tommy Logge of Kent. In France it is called Chabots. 



The-fin rays are 1st, dorsal, 6-9; 2nd, 17 or 1 8 ; 

 pectoral, 15; ventral, 3; anal, 13; caudal, II, all spinous. 



The mouth is wide, jaws nearly equal, in which are 

 many sharp teeth, as well as on the fore-part of the vomer ; 

 the irides yellow ; pupils dark blue ; on the preoperculum 

 there is one spine, which is curved upwards. The dorsal 

 fins are united by a membrane. All the rays of the fins 

 are spotted. Colour of the body brownish-black ; sides 

 lighter, with small black spots ; under-surface of the head 

 and belly white. Spawns March and April. 



THE STICKLEBACKS. 



The STICKLEBACK, Gasterosteus, Gasterosteidce. Yarrell 

 makes six species : the three-spined, rough-tailed stickle- 

 back, Gasterosteus aculeatus; the half-armed, G. semi-armatus; 

 the smooth-tailed, G. leiurus; the short-spined, G. brachy- 

 centrus; the four-spin ed, G. spinulosus; and the ten-spined, 

 G. pungitius. 



Day (" The Fishes of Great Britain and Ireland ") gives 

 only two species: (i) Gasterosteus aculeatus, the THREE- 



THE THREE-SPINED STICKLEBACK. 



SPINED STICKLEBACK, and (2) Gasterosteus pungitms, the TEN- 

 SPINED STICKLEBACK; and makes six varieties : (i) G. tra- 

 churus; (2) G. semicoloratus ; (3) G. semiarmatus, distin- 

 guished by the want of arming by defensive plates along 

 the sides of the line a very common variety ; (4) G. gym- 

 nurus, the lateral plates extending no farther than the end 

 of the ray of the pectoral fin ; (5) G. brachycentrus, with 



