XVIII HOLOSTEL 503 
ossified, opisthocoelous and fused with the neural arches. The 
metapterygoid bones have a secondary articulation with the 
skull." Maxillae segmented into numerous pieces. Jugular plates 
absent. Branchiostegal rays reduced to three on each side. Teeth 
numerous, slender, and of unequal size. In the larger teeth the 
dentine is intricately folded. Pyloric caeca branched and com- 
pacted together into a gland-hke mass. Air-bladder cellular, but 
its blood is not derived from a posterior aortic arch. 
The only known genus is Lepidosteus, the existing species of 
which frequent the fresh waters of North America.” The common 
or Long-nosed Gar-Pike (LZ. osseus), remarkable for its long and 
slender beak, is generally abundant in the rivers and lakes of the 
United States from Vermont to the Rio Grande, and it may reach 
Fria. 299,—Short-nosed Gar Pike (Lepidostevs platystomus.) <3}. (From Bashford 
Dean, after Goode. ) 
a length of five feet. The “Short-nosed Gar” (LZ. platystomus, 
Giinther) has a much shorter and broader beak, and a similar dis- 
tribution (Fig. 299). The “Great” or “Alligator Gar” (Z. 
viridis, Giinther) has a more southerly habitat, frequenting the 
rivers of the Southern States, Northern Mexico, and Cuba. It 
is by far the largest species, sometimes reaching a length of 8 to 
10 feet. 
Lepidosteus is a voracious Fish, preying upon smaller Fishes, 
and, except in the breeding season, it frequents the deeper parts 
of the rivers or lakes. The Fish is constantly in the habit of 
rising to the surface and emitting bubbles of gas, either through 
the mouth or by the branchial clefts, and it is probable that this 
gas is air which has been previously swallowed at the surface 
and passed into the air-bladder. About May Lepidosteus resorts 
in large numbers to shallower water, where the temperature is 
1 Tt is possible that a similar articulation is present in Lepidotus (Smith Wood- 
ward, Brit. Mus. Cat. Foss. Fishes, iii. p. 79). 
2 Jordan and Evermann, op. cit. p. 108, et. seq. 
