Fishes of the Western North Atlantic 73 



Rhinobatus {Rhinobatits) undulatus Miiller and Henle, Plagiost., 1841: 121, pi. 40 (descr., meas., color, ill., 

 Bahia, Brazil); Dumeril, Hist. Nat. Poiss., j, 1865: 498 (descr., color, Brazil). 



Rhinobatus stellio Jordan and Evermann, Rep. U. S. Comm. Fish. (1895), 1896: 220 (listed, Jamaica, name 

 only); Jordan and Rutter, Proc. Acad. nat. Sci. Philad., 1897: 91 (descr., color, Jamaica); Jordan and 

 Evermann, Bull. U. S. nat. Mus., 47 (3), 1898: 2750 (descr. after Jordan and Rutter, 1897, Jamaica); 

 Engelhardt, ."Vbh. bayer. Akad. Wiss., Suppl. ^ (3), 1913 : loi (range); Norman, Proc. Zool. Soc. Lond., 

 1926: 947 (in Key), 972 (descr., ill. head, Jamaica); Jordan, Evermann and Clark, Rep. U. S. Comm. 

 Fish. (1928), 2, 1930: 23 (listed, Jamaica). Fowler, .Acad. nat. Sci. Philad., 6, 1944: 456 (listed, Ja- 

 maica). 



Rhinobatus pellucens Fowler, Proc. .Acad. nat. Sci. Philad., 6"], 1916: 521 (listed, Trinidad, /ii'//«c^Z!/ perhaps 

 misspelling for perce/kns). 



Probable Synonym : 



Rhinobatus undulatus Osorio, J. Sci. math. phys. nat. Lisboa, (2) j, 1895: 253 (listed, Dahomey, \V. .Afr.). 



Genus Rhinohatos Addendum 



We include here one problematical species reported from Mexico without indi- 

 cation as to whether it is from the Atlantic or the Pacific. 



Rhinohatos spinosus Giinther i 8 70 



Study Material. None. 



Knowledge of this Guitarfish is limited to the original account of a stuffed specimen 

 13 inches long, now in the British Museum (Natural History). ^^ 



Compressed spines with dilated base along median line of back, on shoulder, 

 and above eye and spiracle; entire upper surface rough. Snout much produced, the 

 distance between outer angle of nostrils half of that between mouth and end of snout. 

 Anterior nasal valve not dilated laterally. Mouth nearly straight. Rostral ridges con- 

 fluent, very narrow, with a small and short groove at base and provided with spines 

 in their entire length. Snout white. 



Miss Ethelwyn Trewavas contributes the additional information that the spines 

 along the rostral ridges are thorn-like, pointing rearward, on ovoid bases, and in two 

 irregular series, with smaller ones among and between them. 



According to this description, R. spinosus differs from all others of its genus in 

 the Atlantic and eastern Pacific in the fact that it continues to be spiny along its rostral 

 ridges until it reaches such a large size — unless R. rasus Garman 1908 ** is distinct from 

 R. cemiculus and is similarly characterized. R. spinosus is known at present from the 

 original specimen only. Further discussion of it is best postponed until other specimens, 

 Atlantic or Pacific, come under observation. 



References : 



Rhinobatus spinosus Giinther, Cat. Fish. Brit. Mus., 8, 1870: 518 (descr., Mexico); Garman, Proc. U. S. nat. 

 Mus., J, 1880: 518 (descr. after Gunther, 1870); Jordan and Evermann, Bull. U. S. nat. Mus., 47 



65. Gunther, Cat. Fish. Brit. Mus., 5, 1870: 578. 



66. So far known from one small specimen; see discussion, p. 54. 



