278 MARINE INVERTEBRATES 
it is brick-red above and yellowish beneath. It inhabits rocky shores 
only and is found at low tide on the surface of the rocks, where it is ex- 
posed to the action of the waves and also to the attacks of birds of 
prey, which feed upon it, while C. irroratus, concealed under the rocks 
in the same locality, escapes their depredations. This species is supplied 
to the Newport market, where it is considered preferable to the blue 
crab. Its range is from the eastern end of Long Island to Nova Scotia. 
C. magister. This species inhabits the Pacific coast and ranges from 
Alaska to Lower California. ‘The adult male is from seven to nine inches 
broad and from four to five inches long. The anterior margin of the 
carapace is an almost regular elliptical curve with nine small teeth on 
each side. At the end of the curve a large, pointed tooth projects 
directly outward, and from this the carapace slopes abruptly backward, 
giving a narrow posterior end. The surface of the carapace is undu- 
Cancer magister, the common crab of the Pacific coast; male. 
lated and covered with papille, and is light reddish-brown, shading to 
lighter color in the back. The color of the legs and under surface of the 
animal is yellowish. The claws are toothed above and ribbed at the 
sides. It inhabits sandy bottoms below tide-mark and is the largest and 
most important edible crab of the western coast. 
C. productus, the red crab. This species, like the preceding one, is 
of large size and inhabits the western coast from Alaska to the Gulf of 
California. The carapace is four and a half inches in length, from five 
to seven in breadth, and somewhat elliptical in outline. The teeth on 
the anterior margin are distinctly separate in the adult, but in the 
young appear as wrinklings of the edge of the carapace. The posterior 
margins are concave. In color the animal is dark red above and yellow- 
ish beneath in the adults, but variable in the young, sometimes being 
yellow spotted with red, or banded with red and yellow. It inhabits 
rocky shores. This is an edible crab, but is not taken for the markets, 
C. magister supplying all demands. 
