4 1 8 Memoir Sears Foundation for Marine Research 



to retain both of these genera in recognition of the specific grouping that does exist in 

 this respect, despite the facts that some specimens may show a rudimentary dorsal in 

 one of the Australian species {U. viridis McCuUoch 1 916) in which it is usually lacking 

 and that the dorsal fin may be lacking occasionally in another species from the same 

 general region {U. testaceous Miiller and Henle 1841) in which it is normally present. ^b 

 Also, retention of Urotrygon for the longer-tailed species group with narrower 

 caudal, as contrasted with the shorter-tailed Urolophus with broader caudal, seems sim- 

 ilarly justifiable for the time being on the basis of convenience, though it is likely that 

 no definite line of demarkation can be drawn between the two. But the minor difference 

 on which Garman*' separated his new genus Urobatis ("snout not produced") from 

 Urolophus ("snout little produced") seems to us to be of specific significance at most. 



Genus Urolophus Mtiller and Henle 1837 



Urolophus Muller and Henle, S. B. Akad. Wiss. Berl., 1837: 17; Charlesworth Mag. nat. Hist., 2, 1838: 90; 

 type species, Raja cruciata Lacepede, New Holland (old name for Australia), designated by Muller and 

 Henle. 



Generic Synonyms: 



Raja (in part) LacepMe, Ann. Mus. Hist. nat. Paris, 4, 1804: no, for Raja cruciata LacepMe, Australia; 

 Bancroft, Zool. J., 5, 1830: 83, for Trygon sloani^^ Cuvier 1817. 



Leiobatu! Blainville, Bull. Soc. philom. Paris, 1 8 16: 121; type species. Raja cruciata Lacepede 1804.*' 



Trygon (in part) Cuvier, Regne Anim., 2, 1817: 137, footnote; for T.jamaicensis Cuvier, by ref. to Sloane 

 (Hist. Jamaica, 2, 1725: pi. 246, fig. l). 



Trygonobatus Desmarest, Mem. Soc. Linn. Paris, 2, 1823: 6; type species, T.torpedinus Desmarest. Cuba. 



Leiobatis Blainville, in VieiUot, Faune Frang., Poiss., 1825: 43; apparently emended spelling for Leiobatus 

 Blainville 1816. 



Urobatis Garman, Mem. Harv. Mus. comp. Zool., j6, 191 3: 401; type species, U.sloani Garman,'" desig- 

 nated by Garman. Haiti. 



Urotrygon Breder, Bull. Bingham oceanogr. Coll., J (i), 1927: 6; for Trygon jamaicensis Cuvier 1817. 



Not Raja Linnaeus, Syst. Nat., I, 1758, which see, p. 138. 



Not Leiobatus Rafinesque, Caratt. Gen. Spec. Sicil., 1 810: 16; equals Rkinobatos Link 1790, which see, p. 50. 



Not Tri)gonobatus Blainville, Bull. Soc. philom. Paris, 18 16: 112; equals Dasyatis Rafinesque (Caratt. Gen. 

 Spec. Sicil., 18 10: 16), which see, p. 340. 



Not Urotrygon Gill, Proc. Acad. nat. Sci. Philad., 1863: 173; which see, p. 427. 



Generic Characters. Disc ranging from a little longer than broad to about 1.25 

 times broader than long; lateral margins arcuate, without definite outer corners; median 



86. In this we follow Garman (Mem. Harv. Mus. comp. Zool., 36, 1913). 



87. Garman, Mem. Harv. Mus. comp. Zool., 36, 1913: 401, 407. 



88. Prohnhly jamaicensis Cuvier 1817 was intended actually, for Cuvier never used the specific name sloani, so far as 

 we can learn. 



89. Leiobatus sloani Blainville, designated by Jordan (Genera Fish., i, 1917: 95) as type of Blainville's Leiobatus, was a 

 nomen nudum and hence is not available. In its place we propose L. cruciata Blainville, equivalent to Raja cruciata 

 Lacepede 1804, as the only one of the three nominal species included by Blainville, an account of which had ap- 

 peared previously. 



90. Probably this was the Ray referred to by Blainville (Bull. Soc. philom. Paris, 1816: 121) as Leiobatus sloani and 

 by Bancroft (Zool. J., 5, 1830: 83) as Raja sloani. But neither of these early notices was accompanied by any de- 

 scription or by any mention of Sloane's (Hist. Jamaica, 2, 1725: 227, pi. 246, fig. i) pre-Linnaean account of the 

 Jamaican Ray to which they probably referred. Therefore sloani was a nomen nudum until revived by Garman in 

 1913. 



