EXTERNAL CHARACTERISTICS 5 



c-1. A row of large thorns on the midline of the back either 

 on the rear part of the disk, or on the tail, or on both. 

 d-1. The anterior angle of the disk is much greater than 

 a right angle. The entire dorsal surface more or 

 less covered with spines, the midline having large 

 spines behind the shoulders. The Prickly Skate, 

 Eaja scabrata Garman. 

 d-2. The anterior angle of the disk roughly a right angle, 

 the snout hardly projecting, relatively blunt. Dor- 

 sal surface with few, but large thorns, the midline 

 having large spines on the disk and the tail. The 

 outer corners of the disk are bluntly angular. Brier 

 Skate, Eaja eglanteria Bosc. 

 d-3. The anterior angle of the disk roughly a right 

 angle. The thorns are few and small; the midline 

 having thorns on the disk as well as on the tail. 

 Tip of snout sharp-pointed. Outer corners of disk 

 rounded. Rare. Smooth Skate, Eaja senta Gar- 

 man. 

 d-4. The anterior angle rf the disk more acute than a 

 right angle. The long, blunt tipped, snout project- 

 ing. Midline with thorns only on the tail; all 

 thorns small. Barn-door Skate, Eaja stabiiUforis 

 Garman. 

 c-2. Without a row of large thorns directly on the midline 

 of the dorsal surface. Several rows may be present 

 on either side. 



e-1. About 50 rows of teeth, the dorsal surface brown 

 with dark spots. Little Skate, Eaja erinacea 

 Mitchill. 

 e-2. About 90 rows of teeth, the dorsal surface usually 

 with two large, whitish, round spots near the pos- 

 terior angles of the disk. Spotted Skate, Eaja 

 diaphanes Mitchill. 

 b-2. A large trinagular caudal fin and two dorsal fins on the 

 tail. The torpedo. Family Torpedinidae. Electric 

 Skate Narcacion nobilianus Bonaparte. 

 a-2. The tail with a long dorsal spine (the sting-ray). 



f-1. A dorsal fin on the tail in front of the long 

 spine. Family Myliobatidae. Cow-nosed Ray. 

 Ehinoptera qiiadriloda Le Sueur. 



