Fishes of the Western North Atlantic 



441 



anterior spine (when there are two) posterior to axils of pelvics by a distance about as 

 great as distance between eyes; lateral teeth directed strongly rearward and so close 

 together as to form a nearly continuous cutting edge outwardly. 



Skin, apart from tail spine, perfectly smooth on small specimens; but larger individ- 

 uals of both sexes with a row of low oval tubercles along midline of back in shoulder 



Figure 103. Myliobatis freminvillii. A Upper teeth (above) 

 and lower teeth (below) of male, 705 mm wide, from Rio de 

 Janeiro, Brazil (Harv. Mus. Comp. ZooL, No. 400), about 

 1 .9 X . B Tip and middle part of tail spine of specimen from 

 Woods Hole, Massachusetts (U. S. Nat. Mus., No. 22783), 

 about 7 X . 



region, at first 3-4, finally 7—8 ; males at maturity also with one prominent conical 

 tubercle on margin of orbit above eye, the tip alone emerging from the skin. 



Median zone of upper surface of head conspicuously concave from forehead rear- 

 ward to level of posterior ends of spiracles. Distance from level of front of orbits to 

 front of subrostral fin about 0.7—0.8 as great as distance between orbits in females; 

 1. 0—1.2 times in adult males. Orbits not prominent; about 50—62 '/o ^s long as distance 

 between them. Spiracles much longer than broad, at about same level as orbits on sides 

 of head, about twice (1.9— 2.1 times) as long as horizontal diameter of eye and a little 

 longer than orbits. Anterior margins of gill openings sinuous (Fig. 1 02 C) ; first to fourth 



