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 flat disk, with a thin and slender tail. 

 Spiracles always present. Five 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." 



(RATS.) 



PBiSTnm 



• ( The snout is produced into an exceedingly long, 

 t lamina, armed wit 

 along each edge, (saw)." 



flat lamina, armed with a series of strong teeth 



KEINOBATID^L 



" 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." 



