4 
Under a system which, though simple, is sufficiently com¬ 
prehensive for the present purpose, the primary divisions 
are:— 
I. Vertebrata. —Mammals, birds, reptiles, batrachians, and 
fishes. 
II. Tunicata. —Ascidians, sea squirts (primitive vertebrates). 
III. Molhisca. —Oysters, cuttles, snails, slugs, &c. 
IV. Arthropoda. —Lobsters, crabs, spiders, insects, &c. 
V. Echinodermata. —Starfish, crinoids, sea urchins, &c. 
VI. Vermes. —Worms. 
VII. Coelenterata. —Hydras, polyps, corals, sea anemones, jelly¬ 
fish, &c. 
VIII. Spongice. —Sponges. 
IX. Protozoa. —Amoeba, infusoria, rhizopods, &c.; the lowest 
forms of animal life, many of them mi¬ 
croscopic, and bordering closely on the 
vegetable world. 
At the present time about 386,000 species of living ani¬ 
mals are known to systematic zoology. Of these 2500 are 
mammals, 12,500 are birds, 4500 reptiles and batrachians, 
and 12,000 fishes. 
It is with these only that the collection in the Garden has 
to deal. The Vertebrates—animals possessing a skeleton of 
bone or cartilage, enclosing cavities in which the soft parts of 
their organization are contained and protected from injury— 
are arranged in classes , according to the nearness with which 
they approach to one of the five great types of structure which 
have been found to exist among them :— 
I. Mammalia. —Animals which suckle their young. 
II. Aves, or birds. 
III. Reptlha. —As turtles, lizards, and serpents. 
IV. Batrachia. —As frogs, toads, and salamanders. 
V. Pisces , or fishes. 
