60 GIANT FISHES 



shoals or droves, and to do great damage to the pearl-oyster 

 beds of Ceylon and elsewhere. The largest individuals, 

 however, are quite harmless to man. 



These rays are ovo-viviparous, the eggs being hatched 

 within the body of the mother, and several young are produced 

 at a birth. 



The Guitar-fishes are not of any great commercial impor- 

 tance, although their skins provide good shagreen or leather. 

 The flesh of the Ulavi is considered nourishing in parts of 

 India, and is eaten both fresh and salted. The oil from the 

 liver is also much valued. The fins of some Guitar-fishes are 

 treated and exported to China to be used for making soup. 



The names " Shovel-nosed Ray ", " Guitar-fish ", " Fiddler 

 Ray ", etc., refer, of course, to the shape of the head and 

 body. The scientific name, Rhynchobatus, means literally 

 " snout skate ", and Rhinobatus, " shark skate ". 



SAW-FISHES. 

 (Family Pristid.e ; Genus Pristis.) Fig. 26. 



Shark-like Rays which are very closely related to the 

 Guitar-fishes, but which have the snout drawn out into a 

 long, flat, blade-like rostrum, armed on either edge with 

 strong " teeth ". The pectoral fins are not joined to the 

 head to the same extent, and are of moderate size. 



Saw-fishes are found in most warm seas, and may enter 

 fresh water. There is an extinct genus found in Cretaceous 

 rocks, but the genus Pristis does not occur in rocks older than 

 those of the Eocene period. 



The larger species grow to a length of at least 20 feet, and 

 individuals of 30 feet or more are sometimes encountered. 



There are about b existing species, mostly occurring in the 

 brackish waters of estuaries or on sandy or muddy stretches 

 close to the shore. The Common Saw-fish or " Pez Sierra " 

 (P. pectinatus) is abundant in the Gulf of Mexico and ascends 

 the lower Mississippi. Another species (P. perroteti) is found 

 for considerable distances up the Zambesi, Shire, and probably 

 in other African rivers, and a third (P. cuspidatus) ascends the 

 larger Indian rivers to well beyond the influence of the tides. 



