GENERA AND SPECIES. 85 



Carassius. Plate xxii. CYPRINID&. 



170. vidgaris, CRUCIAN CARP. Back greenish, sides yellow, abdomen 



reddish white ; lateral line over 30 ; caudal rays 19 

 or more. 



171. auratus, GOLD-FISH. Gold or silver; lateral line under 30; 



caudal rays 19 or less. 



It would seem to be more reasonable to treat these as two 

 varieties of the same species, to which may be added a third, 

 C. gibelio, the Prussian Carp, which differs only in being narrower 

 in build and having a longer lower jaw and the tail more deeply 

 forked. 



In the Crucian Carp and the Prussian Carp the dorsal has i to 4 

 spines, and 14 to 21 rays, the anal has 3 spines and 5 or 6 rays, the 

 caudal has from 19 to 21 rays; the pectorals have from 13 to 18 

 rays, and the ventrals 9 or 10. The pectorals are twice as long as 

 they are broad ; the dorsal begins behind them and over k he 

 ventrals, and ends over the end of the anal. In the lateral line 

 there are from 28 to 35 scales. The upper jaw is the longer ; the 

 snout is blunt and the mouth small, and not reaching to the eye. In 

 habits this fish resembles the Carp, but it thrives in water that would 

 kill any other, and is generally small, rarely exceeding 7 inches in 

 length. 



The Gold-fish is singularly varied in its fin arrangements, but 

 the typical form has 3 or 4 spines and 16 to 18 rays in the dorsal, 

 3 spines and 5 or 6 rays in the anal, 18 or 19 in the caudal, the 

 pectorals having from 16 to 17 rays, and the ventrals 9. The 

 pectorals should be three times as long as they are broad ; the 

 dorsal begins over their tip, which should just reach the base of the 

 ventrals. In the lateral line there are from 26 to 30 scales. As a 

 rule both jaws are alike, and the mouth is small. Gold-fish are 

 generally kept in tanks or glass bowls, and lead an artificial sort of 

 life, feeding on worms, insects of all sorts and in all stages, 

 generally as pupae, and occasionally shredded meat and even grain. 

 In any water except rain-water be it from the tap, the pump, the 

 stream, or the steam-engine, provided it is kept by frequent change 

 or continual movement from becoming stagnant, they linger for 

 years, but only really thrive in tanks or pools in which there are 

 shady depths in which they can shelter. In such places they will 

 reach n inches in length. In colour the Gold-fish is gold or silver, 

 or red or white with gold, silver, or red markings, the colour 

 seeming to vary with the temperature, the warmer the water the 

 more golden being the fish, the handsomest and healthiest examples 

 being found in the pools in which waste steam is condensed, where 

 the average temperature is 80 degrees. 



Carcharias. Plate xxviii. CARCHARIID&. 



222. glaucus, BLUE SHARK. Pectorals long and pointed ; caudal 

 large, upper lobe notched. 



The Blue Shark has two dorsal fins, the first in the middle of the 

 back, the second above the anal close to the tail ; the ventrals are 



