290 Ayres* Enumeration of the 



bly found two of these spines and no more. They vary indeed 

 in length but not in number, and are always placed in close 

 connection, one immediately over the other. Dr. Dekay, 

 however, describes his specimen as having three spines, of 

 which the first is three inches from the second. But as in his 

 characteristics, he says the tail is '' armed with two or more 

 spines," it is possible that the number " three " is only an ac- 

 cidental variation. 



It appears to me that Dr. Dekay has not acted wisely in 

 rejecting Mitchill's name, especially as he has adopted many 

 of his specific names where there is no more to guide us in 

 determining the species than we have in this instance. But 

 as he has given a description, accompanied by a good figure, 

 of his fish, I have judged it better to adopt the name, hastata, 

 proposed by him. 



Myliobatis bispinosus. Storer. 



Plate XIII. Fig 1. 



This species, the smooth-tailed sting ray of the fishermen, is 

 much less common than the last, and may indeed be con- 

 sidered very rare. I have seen but one specimen ; this was 

 caught July 17, 1841, and was three feet eleven inches in 

 length. It is a very clearly marked species, and as Dr. Storer 

 was obliged to draw up his account from imperfect materials, 

 I have prepared a description and drawing, taken from the 

 specimen which I obtained on Long Island. 



Entire length three feet eleven inches ; length exclusive of the tail one 

 foot six inches ; breadth across the pectorals two feet five inches. Dis- 

 tance between the eyes four and a quarter inches ; eyes vertical, elliptical, 

 greatest diameter one inch, least diameter three quarters. On the summit 

 of the orbit of each eye is a hard, blunt, vertical projection, about one 

 eighth of an inch in height, nearly white at the extremity. 



Body above, smooth, entirely destitute of spines, even on the dorsal 

 ridge. Color of the whole body and head above, reddish brown ; tail 

 lighter at the base, but nearly black towards the tip ; color beneath, 

 whitish. * 



The head is rounded anteriorly, and extends backward, widening but 

 little, for four and a half inches, until opposite the eyes where it joins the 

 body. Mouth two inches in breadth, situated four inches posterior to the 



