418 



ZOOLOGICAL SOCIETY BULLETIN. 



scales. All existing sturgeons 

 are at once distinguishable 

 by their five rows of heavy, 

 boil}' scales. The sturgeon is 

 quite an active species, often 

 leaping clear out of the water. 

 It was once the basis of a very 

 important fishery in the Hud- 

 son River. 



FLASHLIGHT PHOTOGRAPH OP ROCK-BASS. 



ed. It ascends the Delaware to the boundary 

 of New York State. In Europe the same 

 species sometimes attains a length of eighteen 

 feet. 



These large and important fishes are en- 

 tirely inoffensive. Their mouths, devoid of 

 teeth and situated on the under surface of 

 the head and well back of the snout, are 

 sucker-like in form, and can be protruded 

 downwards like those of suckers. They are 

 bottom feeders, eating small mollusks, worms, 

 crustaceans, limited quantities of snuill fislies, 

 and more or less small 

 plant life. The snout is 

 used more or less for stir- 

 ring up the bottom and 

 there is usually consider- 

 able mud to be found in the 

 stomach. These fishes might 

 live in captivity for longer 

 periods if it were practica- 

 ble to keep them in mud- 

 bottomed pools. 



The sturgeons, like the 

 gars and dogfish, referred 

 to elsewhere in this Bult^e- 

 TiN, are fishes of ancient 

 lineage, the species having 

 been more numerous in for- 

 mer times, when many 

 fishes, at least those known 

 to us as fossil forms, were 

 heavilvarnioured with bonv 



A TAME LOON. 



A loon or great northern 

 diver, was received at the 

 Aquarium in September, 1907, 

 where it was kept in one of the 

 large salt-water pools which 

 contained at the same time a 

 collection of dogfish, (Squa- 

 lus), skates and sculpins, for 

 about a month. Although the loon was sup- 

 plied with an abundance of live killifishes, 

 its activity led it to strike frequently at the 

 large fishes, and it succeeded in swallowing 

 one sculpin with a head larger than its own. 

 Even with a dry platform on which to rest, 

 it never left the water of its own accord. In 

 exploring the bottom of the pool, or in pursuit 

 of killifishes, it swam underwatcrK'i//; theimigs 

 clonelij folded — never in use, and it spent much 

 time swimming on the surface liith the ejics 

 submcfiicd watching the large fishes below. 



THE AQUARIUM BUILDING IN 1S50. 

 From an old print. 



