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Kingdom ANIMALIA. 
i fea Animal Kingdom consists of all the organized beings possessed of a mouth and internal digestive 
cavity. By these characters they are excluded from the Vegetable Kingdom, which contains all the 
rest of the organic creation. 
The Animal Kingdom is divided into four Sub-kingdoms: Ist, Radiata; 2nd, Articulata; 8rd, Mol- 
lusca; and 4th, Vertebrata. Examples of all occur in the Paleozoic Rocks. 
Ist Sub-kingdom RADIATA. 
This sub-kingdom comprises a vast number of the lowest organised forms of animal life. One great section, 
named Acrita by Prof. Owen, shewing no trace of a nervous system, being capable of increase by spontaneous 
fission, and by buds, as well as by ova, and having only one opening to the digestive cavity. The higher sec- 
tion, named NVematonewra by the same author, from having a rudimentary nervous system of threads, without 
ganglions or distinct nervous centres, is generally speaking increased by ova alone, and has two openings to 
a distinctly-walled digestive cavity. This 2nd group comprehends the Rotifera, Echinodermata, Polyzoa, and 
Entozoa—some of the last being the most highly organized, and approaching the true worms in many points. 
The most universal character of the group Radiata is that which suggested its name, namely, the more or less 
perfect radiated arrangement of all the parts round the mouth as a centre: this appearance is often deceptive, 
but is on the whole scarcely to be met with in any other division of the animal kingdom. The existence 
of distinct nervous threads in the Actiniw, and the progress of discovery shewing every year the existence of 
nervous filaments in others of the Acrita, induce me to leave the Radiata as one group. 
This sub-kingdom is divided into the following Classes: 1st Infusoria ; 2nd, E’ntozoa or intestinal worms ; 
3rd, Zoophyta; 4th, Polyzoa; 5th, Acalephe or sea-jellies ; and 6th, Echinodermata. The first are not known 
in the Paleozoic rocks, and the second and fifth, from the softness of their tissues, cannot be expected 
in the fossil state, though it is probable they may have existed from very early geological periods. 
Sect. L—RADIATA OF THE LOWER PALZOZOIC ROCKS. (Cambrian and Silurian). 
3rd Class, ZOOPHYTA. (Lin.) 
= Anthozoa, Ehrenberg. 
In the lower types of this Class the body is soft, and capable of expansion by water received through the 
mouth ; all the parts, internal and external, perform equally the same functions; respiration is performed by 
the whole surface; no circulation has been discovered, nor organs of sense, nor distinction of sex; the indi- 
viduals are essentially composed of a closed tubular stomach terminating in a mouth and circle of tentacles. 
B 
