452 Memoir Sears Foundation for Marine Research 



rows of short blunt papillae, 7-8 in the anterior row, 3-6 in the posterior row; floor 

 of mouth with a transverse row of 2-4 slender papillae, continued on either side as a 

 thin fold with irregular margin. Teeth broad transversely; in a single series in each jaw; 

 embryos with one or two of anterior rows in two series (p. 457); teeth of each jaw in 

 close contact with each other from front to rear, thus forming a compact dental plate; 

 the lower plate grinding against the upper by forward-rearward movements of the 

 lower jaw. Anterior and posterior surfaces of gill arches, inward from gill filaments, 

 each with a longitudinal row of tapering papillae, widely spaced. 



Characters otherwise those of the family (p. 433). 



Range. Tropical to warm temperate belts of all oceans in coastwise waters. Red Sea; 

 Indian Ocean in general, southward in its western side to Natal and Madagascar; 

 Malayan-East Indian region; Philippines; Queensland and New South Wales; Cochin- 

 China and southern Chinese Coast; Melanesian, Micronesian, and Polynesian groups, 

 including Hawaiian Islands; west coast of America from Panama and the Galapagos 

 Islands to Gulf of California, and to Oregon as a stray ;55 Atlantic from Brazil northward 

 to North Carolina, occasionally to Chesapeake Bay (p. 462) in the western side; Angola 

 (about Lat. 1 1° S) to the vicinity of Cape Verde in the eastern Atlantic. 



Species. The only species of the genus known in the western Atlantic, Aetobatus 

 narinari (Euphrasen) 1790, appears to be cosmopolitan in suitable situations in tropical- 

 subtropical latitudes, not only in both sides of the Atlantic but across the whole breadth 

 of the Indo-Pacific as well, from East Africa and the Red Sea to the west coast of Central 

 America. A second species, Aetobatus flagellum (Bloch and Schneider) 1801, seemingly 

 distinguishable from A. narinari by its plain coloration and by its more or less prickly 

 disc and tail, which was originally described from the Coromandel Coast, has been 

 reported from the eastern tropical Atlantic «« (apparently with justice) as well as from 

 the Bay of Bengal, Red Sea, Indian Ocean, China, East Indies, and Hawaii." 



It is certain that most of the reports of Aetobatus (as here understood), regardless 

 of the part of the world in which they were taken, refer to one or the other of these two 

 species. However, it is possible that some from the Indo-Pacific may have been based 

 on a third species which has masqueraded as A. narinari (or as one of the synonyms of 

 the latter) because of its spotted coloration but which is separable from A. narinari and 

 from A. flagellum by the lack of a tail spine; a South Seas specimen thus characterized 

 has been reported recently as A. ocellatus (Kuhl) i 823.'^« But the specimen may have been 

 one in which the scar caused by the loss of the tail spine had healed over entirely, or 

 it may have been an abnormal individual. Also, the specific name guttata (Shaw) 1804 

 as distinct from narinari has been applied^' to an Indian Aetobatus with the spots confined 

 to the posterior part of the disc and with conical subrostral fin, but this seems to us likely 

 to fall within the limits of variation of A. narinari.^" 



55. Dimick, Copeia, 1944: 185. 56. Rochebrune, Act. Soc. linn. Bordeaux, (4) 6, 1882: 56. 



57. For list of Indo-Pacific localities for A. flagellum, see Fowler (Bull. U. S. nat. Mus., 100 [13], 1941 : 473). 



58. Fowler, Bull. U.S. nat. Mus., 100 {13), 1941: 475. 



59. By Annandale, Mem. Indian Mus., 2, 1909: 55, fig. loB, 56. 



60. The form described by Garman (Mem. Harv. Mus. comp. Zool., 36, 1913: 442) as Aetobatus ocellatus, new species, 



