MUD-CRABS 281 



apart. They are also taken by a hooked iron which is thrust into the 

 hole ; the crab seizes it and is then suddenly jerked from its hole. The 

 adult measures about three by four and a half inches, and the body 

 is from one inch to two inches thick. One of the chela? is larger than 

 the other, and both are proportionately enormously large, and are tipped 

 with black. The terminal joints of the other four pairs of legs are 

 thickly fringed with hairs and end in points which seem like nails. 



FORMER GENUS Panopeus 



Eupanopeus herbstii, Eurypanopeus depressus, Neopanopctts 

 t&cana, Rhithropanopeus Jiarrisii (Mary J. Rathbun). These four 

 species, formerly all called Panopeus, 

 are small crabs which live in the mud 

 and are commonly known as mud- 

 crabs. They are abundant under stones 

 in muddy places, and occur on the 

 Atlantic coast from Massachusetts Bay 

 to Florida, though they are not com- 

 monly met with north of New Jersey. 

 Eupanopeus herbstii is the largest one 

 of the group, some of the South erp 

 ones measuring two inches across. 

 It is found living in mud at low-water 

 mark, or burrowing in banks near 

 high-tide mark. It is dark olive- 

 brown, the claws broadly tipped with 

 black. Eurypanopeus depressus is flat- 

 tened above, and is smaller than Neo- 



, . -, . EwrypannpfitK (leprfxmtx, the mud-crab ; male. 



panopeus texana, which is somewhat natural size. 



convex above. The last two are com- 

 monly found together and have similar habits. Rhithropanopeus harrisii 

 lives near high-water mark and also in salt-marshes, and is comparatively 

 rare. The claws lack the dark tips of E. herbstii, and a distinct groove 

 follows the edge of the carapace. 



FAMILY GBAPSID.S; 

 GENUS Hemigrapsus 



H. nudus (Mary J. Rathbun). Heterograpsus nudus (Stimpson); H. 

 oregonensis (Mary J. Rathbun), Heterograpsus oregonensis (Stimp- 

 son). These two species, commonly called respectively the purple shore-crab 

 and the yellow shore-crab, are the most abundant species of the California 

 coast. Hundreds may be found congregated under a single rock. They 

 range from Sitka to Lower California. H. oregonensis literally swarms in 

 sloughs of salt or brackish water, and hundreds of uplifted threatening 

 claws confront the intruder who ventures on these mud-flats when the 

 tide is out. This species, the yellow shore-crab, has a nearly square 

 body. The anterior half of the side margins has two rather deep indenta- 



