402 Memoir Sears Foundation for Marine Research 



each side of the posterior spine and 43 (those toward base minute) on each side of the 

 anterior spine on one 1,208 mm wide; it is likely that the teeth are still more numerous 

 on adults. 



Skin, apart from tail spines, perfectly smooth on small and medium-sized spec- 

 imens, but described as more or less roughened on large adults.-" 



Figure 96. Gymnura altaiiela. A Upper teeth from near center of jaw of female, 549 mm wide, from Rio de 

 Janeiro (Harv. Mus. Comp. Zool., No. 533), about i6x. 5 Upper teeth from near center of jaw of immature 

 male, 1,208 mm broad, from Woods Hole, Massachusetts (U. S. Nat. Mus., No. 85956), about 14X • C Upper 

 surface of tail of female, 549 mm wide, from Rio de Janeiro (Harv. Mus. Comp. Zool., No. 533), and D Same 

 of male, 473 mm wide, from Barnegat, New Jersey (U. S. Nat. Mus., No. 104909) to show variation in number 

 of tail spines, about 1.4 X. E Tip and middle part of tail spine of male, 1,208 mm wide, from Woods Hole, 

 Massachusetts (U. S. Nat. Mus., No. 85956), and F Cross section of same, about 3.7 X. 



Snout anterior to orbits a little more than half (55—57 %) as long as distance 

 between outer margins of orbits (thus considerably shorter relatively than in G. micrura, 

 where this proportion usually ranges between 70 and 90*/o); its length in front of 



20. Described as "shagreened" by Lesueur (J. Acad. nat. Sci. Philad., i, 1817: 42) and as "rugueux" on the central 

 part of the disc by Rochebrune (Act. Soc. linn. Bordeaux, [4] 6, 1882: 55) for his G. 'vaillanli, which is probably 

 not distinguishable from altanjela (see discussion, p. 399). 



