53 ^ 
SHARKS AND RAYS. 
the rays in the same particular. Each contains but a single existing genus, and 
the first is unknown previous to the present epoch. 
Side-Giiied The four species belonging to the first family, one of which 
Saw-Fishes. (Pristiopltorus japonicus) is shown in the illustration, are com¬ 
paratively small fishes confined to the Japanese and Australian seas. Having the 
body scarcely depressed, and the pectoral fins of moderate dimensions, and not 
angel-fish ( T V nat. size). 
extending forwards to the head, these saw-fishes are distinguished by the lateral 
position of the gill-clefts, and full development of the so-called prepalatine 
cartilage, and the presence of a pair of long tentacles on the lower aspect of the 
jaw. In habits these fishes probably resemble those of the next genus. 
True Saw-Fishes Distributed over all the warmer seas, the members of this genus, 
among which Pr ist is ant iquorum of the Mediterranean and Atlantic 
is most commonly met with, differ from the last, not only in the inferior position 
of the gill-clefts, but likewise in the small development of the prepalatine 
