CHAP. XX.] 
FISHES. 
457 
Family 89. — SYNGNATHIDAL. (15 Genera, 112 Species.) 
“ Marine Lophobranchii, with very small gill opening and one 
soft dorsal fin.” 
Distribution. — All the tropical and temperate seas. Some 
species of Syngnathus, Doryichthys, and Cmlonotus enter fresh 
water, and a few live in it exclusively. Siphonostoma , Syngna- 
thus, Nerophis, and Hippocampus are British genera. The 
Hippocampina (5 genera, 25 sp.), or Sea-horses, are peculiar to 
the Indian and Pacific Oceans, except three or four species of 
Hippocampus in the Atlantic and Mediterranean. 
Order VI.—PLEGTOQNATHL 
“Fishes covered with rough scales or shields, having a 
narrow mouth, and soft posterior dorsal fin.” 
Family 90. — SCLEBODEKMI, (7 Genera, 95 Species.) 
“ Marine Plectognathi, with toothed jaws.” 
Distribution. — Temperate and Tropical seas, but much more 
abundant in the Tropics. 
Family 91.— GYMNODOOTES. (10 Genera, 82 Species.) 
“ Marine or fresh- water Plectognathi, with jaws modified into 
a beak.” 
Distribution. — Temperate and tropical regions. 
Some species of Tctrodon are found in the rivers of Tropical 
America, Africa, and Asia. Species of Tctrodon and Ortha- 
goriscus have been found on the British coasts. 
