N. ZOOL. GAL.] 
Class III. 
Myriapoda. 
Glomeridae—12 
Iulidae—12 
Polidesmidae—12 
Scutigeridse—12 
Scolopendridae—12 
Geophilidae—12 
Class IV. 
Cru s t ACe a. 
Sect. L Podoph- 
THA-LMA. 
Ord. I. Decapoda. 
A. Brachyura. 
Oxyrhynchi—13, 14 
Cyclometopes—14,15. 
16, 17 
Catametopes—17> 18 
NATURAL HISTORY. 
Oxystomes—19 
B. Macroura . 
Apterura--19 
Pterygura—20 
Scutata—20 
Thalassina—21 
Astacidae—21 
Silicoeidae—22 
Ord. II. Stomato- 
PODA. 
Squillidae—12 
Phyllosomidae — 12 
Alimidae—12 
Section II. Edrioph 
T HALM A. 
Ord. I. Arthros- 
TRACA. 
Amphipoda. 
159 
Gammaridae—12 
Typhinidas—12 
Laemodipoda—12 
Isopoda. 
Epicaridae 
Cymothoidae —12 
Asellinidae—12 
Oniscidae—12 
Ord. II. Entomos- 
TRACA. 
Siphonostoma—22 
Lophyropoda—22 
Phyllopoda—22 
Pcecilopoda—22 
Cirripedes—23 and 24 
THE FIFTH PvOOM 
Contains the hard cases of the Annulose Animals which 
are destitute of jointed feet, and are only provided 
with bristles to assist them in moving from place to 
place. The species are very numerous, as may be seen 
by the specimens kept in spirits in the Ninth Room of the 
Old House, but only a few of them, as the Amphitrite 
and the Serpula , have cases for their protection. The 
cases of the Amphitrites only consist of a membrana¬ 
ceous tube, which being deposited in a fluid state, attaches 
the stones, sand, and other neighbouring bodies to its 
outer surface. These bodies add to the strength of the 
tube, and also assist in concealing the animal from fishes 
and other rapacious animals. It is doubtless for the same 
reason that the larvae of the Caddis Fly found in ponds 
make cases of a somewhat similar structure. The cases 
of the Serpula and allied genera are hard, like shells, 
and formed in the same manner by the deposition of a 
quantity of animal matter mixed with a chalky secretion, 
proceeding from the glands on the surface of the animal. 
As the animal enlarges in growth, and requires a larger 
case for its protection, it continually adds new layers of 
this matter near the end of the shell where its head is 
placed, and drawing its enlarged body forwards, gradually 
