50 
ROOM X. 
Nat. Hist. 
In the Windows are placed some large specimens of 
Snakes, as the Indian Rock Snake (Python), a large 
Rattle-Snake (Crotalus), and two Snakes, the Mourn¬ 
ing Snake (Coluber pullatus) and the Crimson-sided 
Snake (Coluber porphyriacus)• 
In the Table Cases, in the centre of the room, are 
arranged the General Collection of Radiated Animals. 
The Sea-Eggs are at once known from the Star-Fish 
by the body being covered with a hard shell, formed 
of numerous small pieces, placed on bands, and not pos¬ 
sessing a radiated, or stellar form. The shell is covered 
with moveable spines, which serve the purposes of loco¬ 
motion, and also enable the animals to bury themselves 
in the sand when left on the beach by the retreating 
tide ; it is likewise pierced with rows of minute pores, 
through which are emitted small tentacula with dilated 
ends, by which the animal is enabled to attach itself 
to rocks and other marine bodies. The Sea-Eggs are 
divided into several groups, according to the shape of 
the body, and the position of the mouth and anal ori¬ 
fice. 
In the first group, Spatangus, (Case 1,) the shell is 
nearly heart-shaped, with an oval compressed mouth 
placed in the front part of it on the under side, and the 
other orifice on the hinder margin. The upper part of 
the shell has the pores placed in five short bands, re¬ 
sembling the petals of a flower. The shells of this group 
are thin and brittle, and the mouth of the animal, de¬ 
stitute of teeth, is often surrounded by a series of ten¬ 
tacula. 
In the second group, the mouth is in the centre of the 
under part, and the other orifice placed in or beneath 
the hinder margin. In some of these the shells are 
thin, and the series of pores arranged in vertical bands, 
extending from the top of the shell to the mouth ; as in 
the genus Echinolampas (Case 1). The genus Galerites 
(Case 3), is only found in the fossil state. 
In the Shield Echini, the shell is very solid and thick, 
and supported, internally, by perpendicular columns, so 
that 
