28 
NATURAL HISTORY. [UPPER FLOOR. 
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 line Cancer latro, said to live on the 
nuts of palm trees. Also specimens of the Sea Locust 
(Scyllarus), the Rock Lobsters ( Palinurus ), the Plated 
Lobster ( Galathea ), and the Crab Lobster ( Porcellana ), 
which, from the shortness of their tails, generally resemble 
crabs in appearance; the Scorpion Lobster ( Thalassina ), 
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 
( Valemon ), varying greatly in size. Then follow, (Case 8,) 
the Sea Mantes (Squilla), the glass-like Alima, and thePhyl- 
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 ( Cymothoa ), 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, presented 
by J. Reeves , Esq., and a Lobster from the mouth of the 
Thames, presented by IV. Yarrel, Esq. 
The second Table in this room contains a few insects, 
selected from the duplicates of the general collection (see 
p. 26, note), illustrative of the orders and genera of the 
class. 
The coloured line immediately beneath the name of the 
insect, denotes the country where it is found, thus: 
Light Blue . Europe. 
Bed . . Asia. 
Black . . Africa. 
Green . . N.America. 
Yellow . S. America. 
Orange . West Indies. 
Brown . New Holland. 
DarkBlne, England. 
