28 NATURAL HISTORY. [uPPER FLOOR. 
Land Crabs ( Gecarcinus), live in holes *in the earth, espe¬ 
cially 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 {Leiicosid) ; Sea 
Spiders {Leptopodid)^ with their very long legs ; Crested 
Crabs (Calappd)^ 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 {Dorima), 
' Cases 5, 6, and 7 contain the Exochnata, or Long¬ 
tailed Crustacea, as the Lobsters and Shrimps; amongst 
which, those of the genus Hippa have the extremity of 
the tail simple. The Soldier Crabs live principally 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 Cancer latro, said to live on the 
nuts of palm trees. Also specimens of the Sea Locust 
(Scyllarus), the Rock Lobsters (Palinurus)j the Plated 
Lobster (Galathea), and the Crab Lobster {Porcellana)., 
which, from the shortness of their tails, generally resemble 
crabs in appearance j the Scorpion Lobster {Thalassina^i 
which lives great part of its life on land, and destroys the 
new made roads in India by the excavations it forms under 
them ; Lobsters {Astacus), one specimen exhibited was 
pale red, nearly of its present colour when alive ; Shrimps 
( Falemon), varying greatly in size. Then follow, (Case 8,) 
the Sea Mantes {Sqiiilla)^ the glass-like Alima, and the Phyl- 
losoma, with its shell scarcely thicker than a piece of paper. 
The rest of this Table is filled with the Crustacea which 
have sessile, immovable eyes, as, the fresh water Shrimps 
(Gammarus), the Whale Lice {Cyamus), the Wood Lice 
{Oniscus), Sea Bulls {Cymotima), and the King Crab, 
whose style at the end of the body serves the animal as a 
means of defence, and is used by the natives of America 
to form points to their arrows. On the Wall, over the 
mantel piece, is a large King Crab from China, 
hy J. Reeves^ Esq,, and a Lobster from the mouth of the 
Thames, prese?ited by W, Yarrel, Esq, 
