The True Sharks 207 
snout prolonged into a very long and strong flat blade, with 
a series of strong enameled teeth implanted in sockets along 
either side of it. These teeth are much larger and much less 
sharp than in the sawsharks, but they are certainly homolo- 
gous with these, and the two groups must have a common de- 
scent, distinct from that of the other rays. Doubtless when 
taxonomy is a more refined art they will constitute a small 
suborder together. This character of enameled teeth on the 
snout would seem of more importance than the position of the 
gill-openings or even the flattening and expansion of the body. 
The true teeth in the sawfishes are blunt and close-set, pave- 
ment-like as befitting a ray. (See Fig. 54.) 
The sawfishes are found chiefly in river-mouths of tropi- 
cal America and West Africa: Pristis pectinatus in the West 
Fic. 148.—Sawfish, Pristis pectinatus Latham. Pensacola, Fla. 
Indies; Pristis zephyreus in western Mexico; and Pristis pect- 
natus in the Senegal. They reach a length of ten to twenty feet, 
and with their saws they make great havoc among the schools 
of mullets and sardines on which they feed. The stories of 
their attacks on the whale are without foundation. The writer 
has never found any of the species in the open sea. They 
live chiefly in the brackish water of estuaries and river-mouths. 
Fossil teeth of sawfishes occur in abundance in the Eocene. 
Still older are vertebree from the Upper Cretaceous at Maes- 
tricht. In Propristis schweinfurtht the tooth-sockets are 
not yet calcified. In Sclerorhynchus atavus, from the Upper 
Cretaceous, the teeth are complex in form, with a “crimped” 
or stellate base and a sharp, backward-directed enameled crown. 
Rhinobatide, or Guitar-fishes.— The Rhinobatide (guitar- 
fishes) are long-bodied, shovel-nosed rays, with strong tails; they 
are ovoviviparous, hatching the eggs within the body. The body, 
like that of the shark or sawfish, is covered with nearly uniform 
shagreen. The numerous species abound in all warm seas; they 
are olive-gray in color and feed on small animals of the sea- 
