DECAPODA 397 



0. magister Dana. The edible crab of California. Carapace 12 

 cm. long and 15 cm. wide, with 9 short spines on each side of the anterior 

 margin; color reddish-brown: common below low-water mark on the 

 entire Pacific coast, where it is used for food. 



FAMILY 2. PILUMNIDAE. 



Small dull-colored crabs with the first antennae folded transversely 

 or obliquely, with a nearly round cephalothorax and without swimming 

 periopods: about 15 American genera, mostly southern. 



PANOPEUS* Milne-Edwards. Mud crabs. Carapace slightly broader 

 than long : small, inconspicuous crabs which live on muddy bottoms along 

 the shore, often on oyster beds in brackish water, or even in fresh water ; 

 about 14 American species. 



P. (Neopanopeus M.-Ed.) sayi S. I. Smith (Fig. 631). Carapace 

 somewhat convex, with a dentate anterior border; male abdomen with 

 the terminal segment triangular and somewhat broader than long; 



Fig. 631 Fig. 632 Fig. 633 



Fig. 631 Panopeus sayi (Paulmeier). A, dorsal aspect; B, male abdomen. 

 Fig. 682 Panopeus depressus male abdomen (Paulmeier). Fig. 633 Panopeus 

 herbsti the large claw (Benedict). 



length of carapace 17 mm. ; breadth 22 mm. ; color dark and dull : Massa- 

 chusetts to Florida; common. 



P. (Eurypanopeus M.-Ed.) depressus Smith (Fig. 632). Like 

 P. sayi but with a flatter carapace and with a terminal abdominal seg- 

 ment in the male which forms an equilateral triangle, with arched sides; 

 length of carapace 14 mm. ; breadth 19 mm. : Cape Cod to Florida. 



P. herbsti M.-Ed. (Fig. 633). Carapace with a dentate anterior 

 border and with a tubercle just beneath the first tooth; the larger claw 

 with a stout tubercle at the base of the movable segment; terminal 

 abdominal segment in male rounded ; length of carapace 40 mm. ; breadth 

 60 mm. : Long Island Sound to Florida ; near high- water mark. 



FAMILY 3. POBTUNIDAE. 



Swimming crabs. Carapace broader than long and with a well- 

 defined serrate, anterior margin; the last pair of periopods broad and 



* See "The Genus Panopeus," by James E. Benedict and Mary J. Rathbun, Proc. 

 U. S. Nat. Mus., Vol. 14, p. 355, 1891. 



