80 CRETACEOUS AND TERTIARY FISH. 



are scarcely different in other respects. They have been called 

 Carcharias collata by Eastman. I have not examined any New 

 Jersey material. 



Formation and locality. Known only by Cope's record from 

 the Miocene of Cumberland County. 



Order BATOIDEI. 



THE RAYS. 



Body typically disk-like, broad, flat, margin of disk usually 

 formed by expanded pectorals. Tail comparatively slender. Gill- 

 openings inferior, slit-like, 5 in number. Spiracles present. Ver- 

 tebras cyclospondylous, or each one with internal calcareous 

 lamellae not radiating, arranged in one or more concentric circles 

 or series around central ring. Dorsal fins inserted on tail when 

 present. No anal fin. Caudal fin small or wanting. 



The extremes of specialization in this group widely depart 

 from the typical sharks, though many intergradations render 

 them nearly complete. As many fossils have been found, they 

 probably evolved quite early. Except the Rajidae, most all the 

 members of this group are ovoviviparous. 



Sub-Order SARCURA. 



Tail comparatively thick, with two dorsals and a caudal fin, but 

 no serrated caudal spine. 



About four families are usually admitted, and all represented 

 by at least a few fossils. 



Family PRISTID^. 



THE SAW FISHES. 



Body elongate, depressed. Snout saw-like, much produced, 

 flat, armed with strong teeth on each side set at right angles to 

 its axis. No tentacles. No nictitating membrane. Teeth in 



