438 Memoir Sears Foundatmi for Marine Research 



of its rostral fin, and it differs from all three Atlantic species in the greater length of the 

 inner margins of its pectorals from axil to rear corner.^" A second Pacific-American form 

 (M. peruvianus Garman 1 9 1 3), so far known only from Peru, may eventually prove to 

 fall within the limits of variation of M. goodei, which it resembles closely in the shape 

 of the posterior pectoral corners, in the position and size of the dorsal fin, in its pro- 

 portionate dimensions in general, including the breadth between the gill openings of 

 the posterior pairs," and in its teeth. The status of M. chilensis Philippi 1892 is prob- 

 lematical. ^^ 



Lacking adequate material, we are unable to judge how many good species are 

 actually represented among those of the genus that have been named from the western 

 Pacific and Indian oceans.^' 



Key to Atlantic Species 



I a. Base of dorsal fin nearly or quite (90-100 "/o) ^s long as distance between exposed 

 nostrils; its origin close behind rear limits of pelvics. 



freminvillii Lesueur 1824, p. 438. 

 lb. Base of dorsal fin not more than ^3-^/4 (62-77 "/o) as long as distance between 

 exposed nostrils; its origin posterior to rear limits of pelvics by a distance from 

 1—3 times as long as base of dorsal. 



2 a. Distance between inner ends of fifth gill openings more than 1.5 times as 

 long as distance between exposed nostrils. goodei Garman 1885, p. 446. 

 2 b. Distance between inner ends of fifth gill openings only about i .2 times as long 

 as distance between exposed nostrils. 



aqnila (Linnaeus) 1758. 



Eastern Atlantic, including the Mediterranean; north 

 commonly to northwestern France, less regularly to 

 England and Scotland, and occasionally to southern 

 Norway; also reported from Reunion I. in the south- 

 western Indian Ocean, and from the Natal Coast of 

 South Africa. 



Myliobatis freminvillii Lesueur 1824 



Eagle Ray 



Figures 102, 103 



Study Material. Fifteen specimens, male and female, 170 to 860 mm wide, and 

 two embryos, 140 and 144 mm wide, from: Rio de Janeiro; eastern shore of Virginia; 



lo. Inner margin of pectoral longer than distance between orbits on two M. californicus, 650 and 820 mm wide. 



21. See Carman's illustration (Mem. Harv. Mus. comp. Zool., 36, 1913: pi. 36, fig. 5). For a recent account with referen- 

 ces, see Hildebrand (Bull. U.S. nat. Mus., 189, 1946: 74) as Aetobatus peruvianus. 



22. Garman (Mem. Harv. Mus. comp. Zool., 36, 191 3: 430) has pointed out that this name was based on an abnormal 

 specimen, the relationship of which to other members of the genus cannot be determined from either the description 

 or illustration (Philippi, An. Mus. nac. Chile, i, 1892: 6, pi. 3, fig. i). 



23. For a recent survey of these, including M. aquila (Linnaeus) 1758, see Fowler (Bull. U. S. nat. Mus., 100 [xj], 

 1941: 459, as genus Holorhinus). 



