RAYS 8l 



SEA DEVILS OR DEVIL-FISHES. 



(Family Mobulid^e.) 



Closely related to the Eagle Rays. The disc is broader 

 than long, and the tail comparatively short, slender and 

 whip-like. The front parts of the pectoral fins are separated 

 off to form distinct cephalic or head-fins, which project forward 

 as a pair of horn-like appendages on either side of the mouth. 

 The eyes are at the sides of the head. The mouth is wide, 

 and is placed either at the end of the head or somewhat on 

 its lower surface. The teeth are numerous, very small, set 

 in many rows, and have the form of flat tubercles. There 

 is a small dorsal fin at the base of the tail, but, at the most, 

 only a very rudimentary spine. The skin is more or less 

 rough. 



These are the largest of all the Rays, and are found in 

 tropical and subtropical seas. No extinct forms have yet 

 been discovered. 



MANTA OR GREATER DEVIL-FISH. 



(Genus Manta.) Fig. 31. 



The mouth is very wide, and is placed at the square-cut 

 front end of the head. The teeth are present only in the 

 lower jaw. The skin is roughened with small tubercles. The 

 coloration of the upper surface is brown, and becomes darker 

 as the fish grows old. 



Grows to a width of more than 20 feet across the disc, and 

 attains to a weight of more than 3000 lb. 



There are believed to be several species of Mantas, but only 

 one (M. birostris) is at all well known. This one seems to 

 have a wide distribution. 



Unlike the generality of rays, this enormous creature has 

 to a large extent given up a life on the sea bottom, and spends 

 most of its time swimming at or near the surface, although 

 it does not go very far into the open sea. Mantas are often 

 seen singly or in pairs, but occasionally small schools are 

 encountered. In spite of its somewhat clumsy build, its 



