772 NATURAL HISTOEY OF AQUATIC ANIMALS. 



and from five to six inclies across. The carpus and hand of the big claws are smooth or nearly 

 so, and the external antennae are very large and hairy. The margins of the abdomen and of 

 other parts of the lower surface of the body, as well as the ambulatory feet, are very hairy, and 

 this character, together with the great length and hairiness of the antennae, serves as the best 

 distinguishing feature of the species. Young individuals are more hirsute than adults. The 

 color of the carapax is a dark purplish brown ; the chelipeds in adults are marbled with purplish 

 spots. 



The Pacific Eock Crab does not often occur on the shore between tides j it appears to frequent 

 deeper water than either Gcmeer magister or 0. productus, being abundant in from two to three 

 fathoms, always, however, among rocks. 



The Mud Ceabs— Panopeus Heebstii, Edwards; Panopetts depeesstjs. Smith; Panopetjs 



Sati, Smith; Panopeus Haeeisii, Stimpson. 



Four species of the so-called Mud Crabs occur upon our Atlantic coast: Pemopeus Herbstii 

 ranges from Long Island Sound to Brazil, but is not common north of New Jersey; P. depressus, 

 from Cape Cod toFlorida, and often carried much farther north with oysters; P. 8ayi, associated 

 with the last and having the same range; P. Harrisii, from Massachusetts Bay to Florida. 

 P. MerbsUi is rather the larger species, specimens from Florida and the West Indies measuring 

 fully two inches across the back. The color is a dark olive above, the fingers of the claws being 

 black, though lighter at the tips. This species is occasionally sold as food in the New Orleans 

 markets, and is sometimes used as bait. The other three species are more or less abundant in 

 numerous localities where they could also be obtained as bait. Professor Verrill refers to them 

 as follows : 



"Two small kinds of Crabs are very abundant under the stones, especially where there is some 

 mud. These are dark olive-brown and have the large claws broadly tipped with black. They 

 are often called Mud Crabs on account of their fondness for muddy places. One of these, the 

 Panopeus depressus, is decidedly flattened above, and is usually a little smaller than the second, 

 the Panopeus Sayi, which is somewhat convex above. They are usually found together and have 

 similar habits. A third small species of the same genus is occasionally met with under stones, 

 but lives rather higher up toward high- water mark, and is comparatively rare. This is the 

 Panopeus Harrisii. It can be easily distinguished, for it lacks the black on the ends of the big 

 claws and has a groove along the edge of the front of the carapax, between the eyes. This last 

 species is also found in the salt marshes, and was originally discovered on the marshes of the 

 Charles Eiver, near Boston. All the species of Panopeus are southern forms, extending to Florida, 

 or to the Gulf coast of the Southern States, but they are rare north of Cape Cod, and not found 

 at all on the coast of Maine. They contribute largely to the food of the tautog and other 

 fishes.'" 



The Stone Ceab— Menippe meecbnaeius, Gibbes. 



This is one of the two edible species of Crabs occurring upon the Southern Atlantic coast of 

 the United States, Oallinectes hastatus being the other and more important one, on account of its 

 greater abundance. The recorded range of the Stone Crab is from Charleston Harbor, South 

 Carolina, to Key West, Florida, but the so-called Stone Crabs of the Gulf of Mexico probably 

 belong, in part at least, to the same species, and it has also been recently collected on the coast 

 of North Carolina. 



' 1 Vineyard Sound Report, pp. 312, 313, 1871-'72. 



