6o Memoir Sears Foundation for Marine Research 



fins. And the nostrils are up to 1.5 times as long as the distance between them in some 

 R.horkelii but not more than 1.3 times that in R. productus. It is not possible to make 

 a comparison of the younger stages for lack of information about R. horkelil. 



Size. Evidently this is the largest Guitarfish of the western Atlantic, for the 

 claspers of a male 700 mm long still fall a little short of the tips of the pelvics. A female 

 in our Study Material, 840 mm long, is the largest yet reported; the size at maturity 

 is not known. 



Developmental Stages. The embryos have not been seen, nor have we seen new- 

 born young. 



Habits. Nothing is known. 



Range. Coast of Brazil, perhaps north to the Lesser Antilles. Although R. horkelii 

 has been known to science for more than half a century, and although it is easily dis- 

 tinguishable from both of the other species of its genus that occur in the western Atlantic, 

 all that is known about its geographic distribution is that a few were collected many 

 years ago^' at Rio de Janeiro and at Bahia, Brazil, and that one small specimen has 

 been reported more recently from the Lesser Antilles (St. Eustatius i'), but without 

 sufficient information to establish its specific identity with certainty. 



Synonyms and References: 



Rhinobatus {Rhinobatus) horkelii Miiller and Henle, Plagiost., 1841 : 122, pi. 41 (descr., meas., color, ill., Brazil), 

 192 (color); Dumeril, Hist. Nat. Poiss., I, 1865: 499 (descr., Bahia, Brazil). 



Rhinobatus horkelii'^^ Castelnau, Anim. Nuov. Rares Amer. Sud., Poiss., 1855: 100 (listed, Bahia, Brazil); 

 Giinther, Cat. Fish. Brit. Mus., 8, 1870: 444 (cf. R. undulatus)\ Garman, Proc. U. S. nat. Mus., 3, 

 1880: 518 (descr., color, Brazil); Ribeiro, Arch. Mus. nac. Rio de J., 14, 1907: 175, 207 (diagn., refs., 

 Rio de Janeiro and Bahia, Brazil); Engelhardt, Abh. bayer. .Akad. Wiss., Suppl. 4 (3), 191 3: loi (range); 

 Garman, Mem. Harv. Mus. comp. Zool., j6, 1913: 280 (descr., cf. R. pcrcellens, Rio de Janeiro); 

 Metzelaar, Trop. Atlant. Visschen, 1919: 7 (color, W.Indies, St. Eustatius.'); Ribeiro, Arch. Mus. 

 nac. Rio de J., Fauna Brasil., Peixes, 2(1) Fasc. l, 1923: 31 (diagn., color, cf. R. percellens, Bahia, Brazil); 

 Norman, Proc. Zool. Soc. Lond., 1926: 947 (in Key), 976 (descr., ill. head, Brazil); Jordan, Evermann 

 and Clark, Rep. U. S. Comm. Fish. (1928), i, 1930: 23 (listed, Brazil to St. Eustatius, Windward Is.). 



Rhinohatos lentiginosus (Garman) 1880 



Spotted Guitarfish 



Figures 8, 12B, 14, 15 



Study Material. Thirteen specimens, male and female, 350—577 mm long, from 

 Progresso, Yucatan; Freeport, Texas; Pensacola, Key West, Palmetto Key, Pine Island 

 Sound, Captiva Pass, and New Smyrna Beach, Florida; Charleston, South Carolina; 

 and Cape Lookout, North Carolina; embryo 180 mm long, nearly ready for birth, 

 from Charleston, South Carolina; also 13 specimens from Texas which apparently 

 represent a color variant of this species; all in the collections of Harvard Museum of 

 Comparative Zoology, Museum of Zoology at University of Michigan, and U. S. 

 National Museum. 



47. Those in our Study Material were collected between 1859 and 1872. 48. Also spelled horkeli. 



