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 irroratus, (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 3 ^ 

 inches in length and 5^ 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 23.2 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 i inch long, i ^ inch broad and i 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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