376 NEW-YORK FAUNA. 



Description. Form quadrilateral. Body smooth, elevated in the centre. Head sloping 

 above, divided transversely and laterally into four flattened lobes rounded in front ; the lower 

 lobes rather longest ; the neck with several protuberances. Eyes lateral. Pectoral fins wide, 

 pointed at the lateral angles, excavated posterior to this, and rounded behind. Ventral fins 

 oblong, truncated behind. Dorsal fin small, triangular, and placed on the base of the tail. 

 Mouth wide, with several series of flat hexagonal teeth, of which the middle are largest, 

 elongated. Temporal orifices large. Nostrils situated midway between the mouth and the 

 extremity of the snout. Nasal lobe, truncate, denticulate. Tail long, and exceedingly slen- 

 der ; longer than the body. A slender serrate spine, behind the dorsal fin, on the superior 

 part of the tail. . 



Color. Olive-brown above ; beneath white. 



Length three feet ; of the body alone, 18" 0. Width two feet. 



This is an exceedingly common species about New- York in the autumn. With its powerful 

 spade-like snout, it roots up clams ( V. mercenaria), and crushes them between its flattened 

 teeth, which appear to act upon each other like the cylinders of a rolling mill. In the male, 

 the pectorals are acute behind, and the ventral fins are more obliquely truncated ; the dorsal 

 prominence is not very distinct in the living specimen. The name proposed by Mitchill, 

 although it has the priority in point of date, must yield to that of Lesueur, defective as it is, 

 as the former is unaccompanied with any description. 



{EXTRA-LIMITAL.) 



Genus Myliobatis, Dumeril. Teeth wide, flat, paved. Tail slender, elongated, and armed above 

 with a serrated spine, and furnished vrith a fin. Head prominent beyond the pectorals, which 

 are wide. 

 M. freminvillii. (LEsuErR, Ac. Sc. Vol. 4, p. HI.) Orbit salient, surrounded by an eminence. 

 Ventrals rounded. Olivaceous, with rounded spots. Tail long, filiform, triangular. Width two 

 to three feet. Rhode-Island. 

 M? say. (Id. Ac. Sc. Vol. 1, p. 42.) Suborbicular, olivaceous red above. Teeth dilated, and rhom- 

 boidal at the base. Two elongated vertical opposite fins on the tail, behind the spine. Width 17 

 inches. New-Jersey. 



