-t;« ZOOLOGY. 



while the air-bladder is cellular, lung-like. Fossil species oc- 

 cur with those of Amia in the tertiary rocks of the ^^'est. 

 Lepidosieus ossen.t Agassiz, the bony gar, with along, slender 

 snout, is sometimes five feet long ; L. platystonms Rafin. 

 has a short nose, while the alligator gar, L. spatula Laee- 

 pede, has a short and wide snout, and grows to a larger size 

 (nearly three metres) than tlie other species, and inhabits 

 the Mississipj)i Valley. The garpikes are carnivorous, very 

 rapacious, and are said to destroy large numbers of food- 

 fishes. They usually remain near the surface of the water, 

 emitting bubbles of air and apparentl}' taking in a fresh 

 supj)]y. "Wilder has observed Amia inhaling air, and re- 

 marks thr.t "so far as the experiments go, it seems probable 

 that, with both Amia and Lepidosteus, there occurs an inha- 

 lation as well as exhalation of air at pretty regular intervals, 

 the whole process resembling that of the Menohranchus and 

 other salamanders, and the tadpoles, which, as the gilla 



Fig. .398. — Garpike. From Tenney's Zoology. 



shrmk and the lungs increase, come more frequently to the 

 surface for air. " Both of these fishes are very tenacious of 

 life and withstand removal from water much better than 

 bonyfislies and sturgeons, on account of the lung-like nature 

 of their air-bladder. Wilder shows that there is a series of 

 forms, mostly Ganoids, from the Amia and Lepidosteus in 

 which the pneitmatic duct enters the throat on the dorsal 

 side, up to Lepidosiren in which it enters the throat on the 

 ventral side, like the air-tube or trachea of Amphibians and 

 higher Vertebrates. 



The breeding habits and external changes in form of the 

 garpikes have been described by Mr. A. Agassiz. The gars, 

 which are nocturnal in their habits, appear on the sh'ires of 

 Lake Ontario,near Ogdensburg,in immense numbers between 



