222 
Sub-order II. BATOIDEI. 
“ Gill-openings ventral. In a few of the genera, 
which we place first, the habit is still that of the 
sharks; but the body is depressed; and in the 
typical genera the trunk, which is surrounded by 
the immensely developed pectoral fins, forms a 
broad fiat disk, with a thin and slender tail. 
Spiracles always present. Eive pairs of gill- 
openings. No anal fin ; dorsal fins, if present, on 
the tail. 
” Temperate and tropical seas ; some species 
pelagic ; some entering fresh waters or entirely 
limited to rivers within the tropics.” 
(EATS.) 
PEISTIDfiE. 
“ The snout is produced into an exceedingly long, 
flat lamina, armed with a series of strong teeth 
along each edge, (saw).” 
EHINOBATIBfiE. 
“ Tail strong and long, with two well-developed 
dorsal fins; a caudal and a longitudinal fold on 
each side. Disk not excessively dilated, the rayed 
portion of the pectoral fins not being continued to 
the snout. No electric organ.” 
