216 The True Sharks 
sand; ddo0vs, tooth) would indicate. The way in which the 
jaws lie indicates that these teeth belonged to rays rather than 
sharks. Numerous species have been described, mostly from 
the Subcarboniferous limestones. Archaobatis gigas, perhaps, 
as its name would indicate, the primeval skate, is from the 
Subcarboniferous limestone of Greencastle, Indiana. Teeth 
of numerous species of Psammodus and Copodus are found in 
Fig. 156.—Devil-ray or Sea-devil, Manta birostris (Walbaum). Florida. 
many rocks of Carboniferous age. Psammodus rugosus com- 
mon in Carboniferous rocks of Europe. 
Family Mobulide.—The sea-devils, Mobulide, are the mightiest 
of all the rays, characterized by the development of the anterior 
lobe of the pectorals as a pair of cephalic fins. These stand 
up like horns or ears on the upper part of the head. The teeth 
are small and flat, tubercular, and the whip-like tail is with 
or without spine. The species are few, little known, and in- 
ordinately large, reaching a width of more than twenty feet 
and a weight, according to Risso, of 1250 pounds. When har- 
pooned it is said that they will drag a large boat with great 
swiftness. The manta, or sea-devil, of tropical America is 
