CHAP. XX.] 
FISHES. 
463 
Family 112.— TRYGONID^. (6 Genera, 43 Species.) 
" Rays with the pectoral fins extending to end of snout 
Distribution. — Seas of all temperate and tropical regions, and 
rivers of Tropical America. A species of Trygon has occurred 
on our Southern coast. Ellvpesurus and Tceniura are found in 
the fresh waters of the interior of South America, while the 
latter genus occurs also in the Indian seas, hut not in the 
Atlantic. 
Family 113.— MYLOBATIDiE. (5 Genera, 22 Species.) 
“ Rays with very broad pectoral fins not extending to end 
of snout.” 
Distribution. — Temperate and tropical seas. A species of 
Myliobatis is British, but most of the species and genera are 
confined to tropical seas. DicerdbaMs and Ceratojgtera are very 
large Rays, commonly called Sea-devils. 
Sub-class V.— CYCLOSTOMATA. 
“ Cartilaginous fishes, with suctorial mouths and without 
lateral fins.” 
Family 114— PETROMYZObTlTD^E. (4 Genera, 12 Species.) 
“ Marine or fresh-water eel-like fishes, with suctorial mouths 
and without barbels.” 
Distribution.— Coasts and fresh waters of temperate regions 
of both hemispheres. Three species of Petromyzon (Lampreys), 
are British. 
