The True Sharks 209 
“wheelbarrow-shaped,”’ with a projecting tube at each of the 
four angles. The size of this egg-case depends on the size of 
the species, ranging from three to about eight inches in length. 
In some species more than one egg is included in the same case. 
Most of the species belong to the typical genus Raja, and 
these are especially numerous on the coasts of all northern 
regions, where they are largely used as food. . The flesh, although 
rather coarse and not well flavored, can be improved by hot 
butter, and as “raie au beurre noir’’ is appreciated by the 
epicure. The rays of all have small rounded teeth, set in a close 
pavement. 
Some of the species, known on our coasts as “ barn-door 
skates,’ reach a length of four or five feet. Among these are 
Raja levis and Raja ocellata on our Atlantic coast, Raja binocu- 
as 
Fia. 150.—Common®kate, Raja erinacea Mitchill. Wood’s Hole, Mass. 
lata in California, and Raja tengu in Japan. The small tobacco- 
box skate, brown with black spots, abundant on the New England 
coast, is Raja erinacea. The corresponding species in Cali- 
fornia is Raja inornata, and in Japan Raja kenojet. Numerous 
other species, Raja batis, clavata, circularis, fullonica, etc., 
occur on the coasts of Europe. Some species are variegated in 
color, with eye-like spots or jet-black marblings. Still others, 
living in deep waters, are jet-black with the body very soft and 
