The Spotted Eagle Ray. 297 



Ruppell (1835) gives a drawing of the jaws (text-fig. 8), the first since 

 Sloane (1725), but it is especially to be regretted that he offers no hint as 

 to the kind of food they are used in grinding. 



Agassiz (1836), however, in his figures emphasizes the rough frontal 

 portion of each jaw and explains that this is caused by their rubbing together 

 in feeding ; but even he gives no idea of the food of our ray. His figures are 

 reproduced as text-figures qa and qb in the present paper. 



Owen (1840) figures a longitudinal vertical section through a dried 

 head and jaws of A. narinari, comments upon the projecting lower jaw, 

 and conjectures that it "can be used, like a spade, in digging out shellfish, 

 etc., from the sandy bottoms frequented by these rays." Owen is thus the 

 first writer to approximate the food on which this ray lives. He especially 

 calls attention to the strength of the jaws necessary to support such dense 

 and heavy teeth, saying that in density the jaws of this cartilaginous fish 

 approach true bone. 



Gunther, in his "Introduction to the Study of Fishes" (1880), remarks 

 of the family Myliobatidse that the cephalic fins are supposed to be flexible 

 in the living fish and conjectures that they may be used for scooping up 

 food and conveying it from the bottom to the mouth. By implication this 

 statement refers also to the genus Aetohatus. One hardly knows what to 

 think of this. The cephalic fin is soft and the skin-like covering especially 

 so in narinari; hence if it is used for the purpose indicated by Gunther, it 

 seems that examination of the living fish ought to show the effects of this 

 hard usage in sand and oyster shells on the snouts. Ordinary sting rays not 

 infrequently are found with bloodshot snouts, but the nine specimens of the 

 spotted sting ray examined by me have shown nothing of the kind. Yet there 

 is no doubt that they feed almost wholly on clams, and Coles (1910) says 

 that they use their snouts for rooting in the sand after the fashion of hogs. 



Jordan and Evermann (1896) say of the rays of the family Myliobatidae 

 that they feed on mollusks, crushing these with their large grinding teeth. 

 Jordan in his "Guide to the Study of Fishes" (1905) makes a similar 

 statement, adding that these fish are destructive to oysters and clams. 



Thurston (1894) confirms Jordan by describing the great damage done 

 to the pearl-oyster banks of Ceylon by these rays, the banks being some- 

 times almost ruined by them. However, he speaks of dissecting an A. 

 narinari and finding its stomach full of sea- weed. 



The present writer has elsewhere (Gudger 1910) recorded the fact that 

 the food of A . narinari seems to consist wholly of clams. Dissections of 

 three specimens in 191 1 (Gudger 1912) confirmed this conclusion. How- 

 ever, in not one of the alimentary tracts of the four specimens examined' 

 were any fragments of shells to be found. These observations on its food 

 are confirmed in all respects by dissection of the four Florida specimens. 



The most extensive and definite observations on the food and feeding 

 habits of this ray have been reported by Coles (1910) in the paper elsewhere 

 repeatedly referred to. He suggests the name "sea-hog" for our ray, on 



