NATURAL HISTORY. 
81 
ROOM IV.] 
Ocypode , (Case 17,) which hide in holes in the sand on 
the sea-shore during the day, and leave them at sun-set. 
The genus Pinnotheres, is a very small race of Crustacea, 
inhabiting bivalve shells, and supposed by some of the an¬ 
cients to be consentaneous inmates with the molluscous 
animal, and attached to it by mutual interest. The Painted 
or Land Crabs ( Gecarcinus ), Case 17, live in holes in the 
earth, especially near burying-grounds, and only go to the 
sea during the breeding season; their flesh is considered a 
delicacy, but it sometimes proves deleterious. Besides the 
preceding, there are specimens of the Globular Crabs ( Leu - 
cosia ), Case 19; Sea Spiders ( Leptopodia ), Case 13, with 
their very long legs; Crested Crabs ( Calappa ), having the 
front part of the claws raised into a crest, and the hinder 
part of the shell projecting so as to cover the legs; and 
lastly, those Crabs which have the two hinder pairs of legs 
placed on their back ( Dorippe ), and the Death's-head Crabs 
(Case 19), ( Dromia ). 
Long-tailed Crustacea, (Cases 20, 22,) as the Lobsters 
and Shrimps; amongst which, those of the genus Hippa, 
(Case 20,) have the extremity of the tail simple. The 
Soldier or Hermit Crabs, ( Pagnrus , Case 20,) live prin¬ 
cipally in the cavities of sponges, and also in the mouth of 
spiral shells, occasionally altering the texture of the latter, 
by some unknown process, to such a degree as to render 
them quite soft, and easily penetrable by a common pin. 
Amongst these is a fine specimen of Birgits latro, (Case 20,) 
said to live on the nuts of palm trees. Also specimens of 
the Sea Locust (. Scyllarus ), the Rock Lobsters ( Palinurus ), 
Case 21, the Plated Lobster ( Galathea ), Case 20, and the 
Crab Lobster (Pore ell an ct), which, from the shortness of 
their tails, generally resemble crabs in appearance; the 
Scorpion Lobster (Thalassina), Case 21, which lives 
a great part of its life on land, and destroys the new made 
roads in India by the excavations it forms under them; 
Lobsters (Astacus), Case 21, one of the specimens exhibited 
was pale red, nearly of its present colour when alive; 
Shrimps (Palcemon), Case 22, varying greatly in size. 
The Stomatopodes or Sea Mantis, differ from the JDeca- 
podes in the head being horny and separated from the 
thorax, and in having only three pairs of accessory jaws, 
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