666 GEOLOGICAL SURVEY OF NEW JERSEY. 



TRYGON, Adan. 



(Dasybatis, Walbaum. Dasyatis, Raf.) 



T. centrura, Mitch, (fiastata.) Common Sting Ray. Clam-cracker. 

 Stingaree. 



(T. sayi } Le S., is a more southerly species.) Tail more than 

 twice length of disk (less in sayi) ; round on top, compressed, 

 with lateral series of large tubercles ; snout not prominent ; teeth 

 small ; color brownish. Length, 8 feet. T. sayi is supposed to 

 be young of other species. Varieties of centrura (perhaps young 

 in different stages), with shorter tails, smoother skin, &c., have 

 been distinguished. This species is designated T. sayi by C. C. A. 



" Lesseur describes a specimen of ray from New Jersey, in 

 the Journal of the Philadelphia Academy, which is reported by 

 Prof. Baird to have been very abundant at Beesley's Point. It 

 inflicts a poisonous wound with its tail, if not handled with care." 



Family MYLIOBATIDJE. 



Eagle Rays. 



Disk broad ; pectoral fins not continued to end of snout, but are 

 replaced here by two fleshy " cephalic fins ; " tail very slender ; fin 

 near its root and a spine ; skull raised so eyes and spiracles are lateral ; 

 teeth large, hexangular ; sexes alike. 



MYLIOBATIS, Bum. 



M. freminvillei, Le S. (acuta, Stor., bispinosus, Dum.) Eagle Ray. 



Median teeth very broad; disk broad, equal to length of 

 tail ; skin smooth ; a white prominence over eye ; small teeth in 

 three rows at sides of median ones ; color reddish brown, with 

 black tail. Cape Cod to Brazil. Not uncommon. 



RHINOPTBRA, Kuhl. 



R. quadriloba, Le S. Cow-nosed Ray. 



Disk emarginate on " snout," which bears two lobed " cephalic 



