FISHES. 537 
The White Ray, Rata batis (Fig. 358), reminds us of a lozenge, 
the point of the Rules forming the lower angle, the longest ray of 
each pectoral forming the lateral angles, while the summit of the tail 
forms the last angle; the whole surface seems flat, but a swelling is 
distinguishable towards the head, on the upper surface, which bears, 
Fig. 358.—The White Ray (Raia batis). 
as it were, the contour of the body, properly so called, namely, the 
three cavities of the head, the throat, and the belly, which occupy the 
centre of the lozenge, beyond which the pectoral fins extend. ‘These 
fins, though covered with a thick skin, permit the cartilaginous rays, 
with their articulations, to be very distinctly seen. 
The head of the white ray, which terminates in a muzzle slightly 
pointed, is attached behind to the cavity of the breast. The mouth, 
placed in the lower part of the head and far from the extremity of the 
