The Spotted Eagle Ray. 289 



structures so imperfectly shown that it has not seemed worth while to re- 

 produce it here. 



Forster, whose collections were made 1772 to 1774, but whose work was 

 first made generally known by Lichtenstein in 1844, thus describes the 

 jaw structures of his Raja edentula: 



The lower teeth are of bone joined together like a spatula. These [jaws] are formed of 

 many crescent-shaped bones joined together like tiles by a membrane. These teeth are 

 much longer than the upper ones. The upper teeth are also made up of many bones, much 

 broader than the bones of the lower teeth, and are likewise joined together by a membrane. 



Cantor (1849) remarks upon the obtuse angle made by the teeth of the 

 lower jaw and specifically states that the teeth are a greenish- white, being 

 of the same color as the spots and approaching the greenish-gray or greenish- 

 olive of the dorsal surface. The teeth of all Key West and Beaufort speci- 

 mens examined were white. A possible explanation, however, offers itself 

 for this anomalous color of the teeth of Cantor's fish. While at Tortugas 

 during the summer of 191 3, I had occasion to preserve a set of jaws in 

 formalin in a copper tank. When they were taken out some weeks later, 

 they had become impregnated with the copper salts and like Cantor's 

 specimen were of a distinct greenish white. It may be that his specimens 

 had suffered a similar impregnation. 



Bleeker (1852) remarks that the upper jaw is as wide as long and has 

 13 teeth, while the lower with 16 plates is twice as long as wide. Day, in 

 his "Fishes of Malabar" (1865), in giving the characters of the genus 

 Aetobatis, by some strange error speaks of hexagonal teeth with small 

 lateral ones, these being the teeth characters of the family Myliobatidse. 

 However, in speaking of A. narinari, he correctly describes the dentition, 

 noting that the lower teeth are obtusely angled. 



Dumeril (1865) admirably describes the dental apparatus of the genus, 

 and for A. narinari notes that the teeth of the lower jaw form a very open 

 curve. This is in marked contrast to the sharply angled teeth of the Beaufort 

 and Key West jaws and of Ruppell's Red Sea form, but is in complete 

 agreement with Agassiz and with Cuvier (see text-figs. 9B and 12). 



Gill (1867) records of the Pacific Coast specimen, A. laticeps from San 

 Francisco, that its dental plate had the anterior angle obtusely rounded. 

 However, it must be remembered that Jordan thinks this form a mere 

 variant of A. narinari. 



In Gunther's diagnosis of the genus (1870), in volume 8 of his "Cata- 

 logue," from the study of abundant material, consisting of ten specimens, 

 one set of jaws, and two sets of dental laminae of Aetobatis narinari, he speaks 

 of a single set of teeth in each jaw, the lower projecting beyond the upper. 

 For the species he writes as follows: 



Teeth of the lower jaw are sometimes angularly bent, sometimes nearly straight. Our 

 series of examples shows clearly that this difference is individual and docs not constitute a 

 specific character. 



Of two half-grown specimens from the Seychelles, one had the lower 

 teeth angularly bent, the other nearly straight; except for these differences 



