MARINE AQUARIA 
marks and in tidal pools, but also resorts to the peaty banks on the shore 
and in ditches and streams of salt and brackish waters. In some parts of 
New England it is known as the “Joe Rocker.” Abounds from Cape 
Cod to New Jersey and further south. 
Cancer trroratus, (Say), or Common Rock Crab, may be distinguished 
by the nine blunt teeth on each side of the front margin of the nearly 
smooth carapace, which is evenly sub-oval in outline, two-thirds as long 
as broad. ‘The claws are short and stout and the four posterior legs long 
and rather slender, with pointed tips. The carapace and upper surface of 
the legs are yellowish in color with purplish-brown dots and mottlings at 
the sides and rear. Between tides it burrows in the sand and gravel or is 
concealed among rocks and weeds. Its range is from Labrador to South 
Carolina but occurs most generally above Virginia. 
Cancer borealis, (Stimp.), or Jonah Crab, is closely related to the fore- 
going, and may be distinguished by the rougher carapace and claws, the 
shorter and thicker legs and the bright-red color above and yellowish 
color beneath the carapace, claws and legs. ‘The carapace reaches 31% 
inches in length and 534 inches in breadth. Its habitat is similar to the 
above, but does not occur below the New England States. It lives a 
more exposed existence and is rarely concealed among the rocks. 
Panopeus herbstii, (Edw.), the most common and largest of the Mud 
Crabs, is dark-olive above and yellowish-white below the carapace, and 
has the large claws black, tipped with lighter color. The largest measure 
2 inches across the carapace and range from Massachusetts to Brazil. 
Other smaller Mud Crabs are P. depressus, P. sayi and P. harrisii, all 
ranging along the Middle Atlantic coast as far south as Florida. 
Platyonichus ocellatus, (Lat.), or Lady Crab, Sand Crab, has a 22 to 
3 inches carapace, nearly as long as broad, the form roughly suggesting a 
six-sided figure. The lateral margins bear five spines or teeth and the 
front limbs and claws are long and somewhat slender. ‘The color is dingy- 
white and the back is covered with red and purple spots. It frequents 
the sand of low-water marks and exposed beaches buried to the eyes, and 
feeds on smaller living and dead animals. It is a common feature of the 
sea beach. Found from northern New England to Florida, from low- 
water marks to ten fathoms. 
Ocypoda arenaria, (Rath.), or Sand Crab, Ghost Crab, is a small shore 
crab about 1 inch long, 1% inch broad and 1 inch thick. The carapace 
folds down between the eyes, which are prominent on the long peduncles. 
It burrows in the sand in holes often three feet deep and is very quick in its 
movements when disturbed. It has the habit of raising itself on its feet and 
moving the eyes in its desire to see approaching enemies and prey. The 
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