TORPEDINID^. — XV. 21 



20. RAJA (Artedi) Linnaeus. {Rata or Raja, the Latin name.) 



a. Middle line of back and tail behind shoulders, unarmed in adult, with a row 

 of spines in young; outline of disk before spiracles obtuse, without 

 acute angle at tip of snout. 

 6. Eows of teeth about W. 



25. R. erinacea Mitchill. Common Skate. Tobacco-Box. 

 Spines largest on front of pectorals ; smaller ones on head, back, 

 and shoulder girdle. Light brown, with round dark spots. L. 1^ 

 feet. Smallest and commonest of our skates, from Va. northward. 

 (Lat., hedge-hog.) 



hb. Eows of teeth about M.. 



26. R. ocellata Mitchill. BiG Skate. Similar to preceding, 

 but much larger, and with additional rows of spines along the back 

 and on sides of tail. Light brown, with dark spots ; usually a large 

 white ocellus with a dark centre on P. behind. L, 3 feet. Mass. N. 



aa. Middle line of back and tail with a row of spines at all ages; outline of 

 disk before spiracles forming a more or less marked angle at tip of snout. 

 c. Angle at tip of snout short, obtuse; teeth 44; body and tail with 

 strong -spines with broad stellate bases. 



27. R. radiata Donovan. A median dorsal row of large spines 

 or bucklers ; others about head. L. 1^ to 2 feet. N. Atl. ; rather 

 rare, S. to Cape Cod. (-Em.) 



cc. Angle at tip of snout acute, moderatelj' long ; teeth AO; no coarse spines 

 or bucklers. 



28. R. eglanteria Lacepede. Prickles small and sharp ; a large 

 spine on each shoulder. Brown, with darker bars and blotches. 

 L. 2 feet. Cape Cod southward ; not common. {Eglantine, brier- 

 rose.) 



ccc. Angle at tip of snout much produced, blunt; teeth M.. 



29. R. Isevis Mitchill. Barn-door Skate. Spines of body 

 very few and small, on head and back ; a row of larger ones on 

 median line of tail ; female rougher, as is usual among rays ; snout 

 very long, somewhat spatulate. Color brownish, with paler spots 

 mostly ringed with darker. L. 4 feet. Va. N. ; not rare. (Lat. 

 smooth.) 



Family XV. TORPBDINID^. (The Electric Rays.) 

 Trunk broad and smooth, the tail short and thick, with rayed 

 caudal and usually two rayed dorsals, the first over or behind ven- 

 trals ; a large electric organ made up of hexagonal tubes, between 

 head and pectorals. Genera 6, species 15, found in most warm 

 seas ; noted for their power of giving electric shocks. 



a. Dorsal fins two ; ventrals separate ; spiracleplacednearly an eye's diameter 

 behind ej'e Torpedo, 21. 



