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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 Calif ornia. 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 papillae, 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. 



