ROOM III.] NATURAL HISTORY. 75 
of the younger animal being thin and soft, it gradually 
becomes harder until the animal arrives at its perfect 
state of developement, and then it thickens, blisters, and 
swells until the hole through which the head of the 
animal was emitted is obliterated, and the animals are 
destroyed by the developement of their own skin. These 
cells are to be found gradually spreading from the centre 
of the expansion or the base of the stem of the more tree* 
like coral, while the new animals and their cells are being 
developed on the edge of the frond or the tips of the 
branches. Sometimes, as the mass increases in size, it 
sends up more or less erect lobes, and if these lobes have 
both of their sides equally exposed to the influence of 
the sea and light, so that the animals of each side can 
procure their nourishment, then they form two layers of 
cells applied back to back, as in Eschara . Sometimes the 
new cells are formed on the surface of the older and 
dead ones, so as to form a cylindrical branched coral, 
having all the new pores developed at the ends of the 
branches. 
The upright Cases on the Table Cases are intended to 
contain the large specimens of the skeletons of Zoophytes, 
or Corals, arranged in the same manner as the more com¬ 
plete series in the Tables; and the collection of these 
animals preserved in spirits, (especially those which can¬ 
not be well exhibited in a dry state,) is kept in the Wall 
Cases of the Ninth Room of the old building, until the 
Wall Cases of these Rooms are made. 
The following is a continuation of the Catalogue of the 
genera of radiated animals, (from page 66.) The num¬ 
bers appended indicate the Table Cases in this Room 
which contain the specimens in the collection. 
Section II. 2. Oceamdce, 2. Physophorida. 
IiE i oder mat a. 3. JEquoridcB. Order V. Chondro- 
Class III. 4. Berenicidce . grad a:. 
Acalepha. Order III. Cilio- Fam. 1. Velellidai. 
Order I. Phanero- grada. Velella, Case 1 
carp a. Fam. 1. Beroidce. Porpita, .... 1 
Fam. 1. Rhizostomidce . 2. MnemeicUz. Class IV. 
2. Medusidce . 3. Callianiadce. Zoophyta. 
Order II. Crypto- Order IV. Physo- Ord. I. Zoantharia. 
carp a. grad A. Fam. 1. Actiniadcz 
Fam 1. Geryonida. Fam. 1. Diphyidce. Actinia 
E 2 
