400 Memoir Sears Foundation for Marine Research 



Figure 95. Gymnura altavela. A Male, 1,208 mm wide, from Woods Hole, Massachusetts (U. S. Nat. Mus., 

 No. 85956). B Nostrils, nasal curtain, and mouth of same, about 0.5 x. C Nostrils, nasal curtain, and mouth of 

 male, 473 mm wide, from Barnegat, New Jersey (U. S. Nat. Mus., No. 104909), about 1.4 X. D Eye and 

 spiracle of same, about 3 .4 X . B Side view of tail of same, about i .4 X . F Cross section of tail of same at point 

 marked by the cross line on E, about 5.5 X- 



between the gill openings. The keeled shape of the upper surface of its tail and the 

 presence of spiracular tentacles are the chief characters that separate G. altavela from 

 the somewhat problematical G. hirundo, which is known only from Madeira, unless, 

 indeed, certain Brazilian specimens, reported as G. maclura, actually were G. hirundo 

 (see discussion, p. 398). 



Description. Proportional dimensions in per cent of extreme breadth of disc. Male, 



