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Updated: June 3, 2025
The ANNULOSA. The Carboniferous Insecta and Arachnida are neither less specialized, nor more embryonic, than these that now live, nor are the Liassic Cirripedia and Macrura; while several of the Brachyura, which appear in the Chalk, belong to existing genera; and none exhibit either an intermediate, or an embryonic, character.
The sub-kingdom Annulosa, furnishes good illustrations. Among the lower types the body consists of numerous segments that are alike in nearly every particular.
Among other points of community between the successive rings which make up the body in the lower Annulosa, is the possession of similar pairs of ganglia. These pairs of ganglia, though connected by nerves, are very incompletely dependent on any general controlling power.
That which we may distinguish as transverse integration, is well illustrated among the Annulosa in the development of the nervous system.
The acrita were the first forms of animal life upon earth, the starting point of that great branch of organization. The polypi vaginati, in the crustaceous covering of the living mass, and their more or less articulated structure, represent the annulosa. In the radiated forms of the rotifera, and the simple structure of the polypi rudes, we are reminded of the radiata.
Ascending the scale of life-forms, we next observe the great family of the Annulosa, or jointed creatures, which comprises the various families of the worm, the crab, the spider, the ant, etc. In this great family are grouped nearly four-fifths of the known life-forms.
There is no certainly known extinct order of Protozoa; there is but one among the Coelenterata that of the rugose corals; there is none among the Mollusca; there are three, the Cystidea, Blastoidea, and Edrioasterida, among the Echinoderms; and two, the Trilobita and Eurypterida, among the Crustacea; making altogether five for the great sub-kingdom of Annulosa.
But in the higher Annulosa, called Articulata, sundry of the anterior pairs of ganglia, besides growing larger, unite in one mass; and this great cephalic ganglion having become the co-ordinator of all the creature's movements, there no longer exists much local independence. Now may we not in the growth of a consolidated kingdom out of petty sovereignties or baronies, observe analogous changes?
And here you have evidence of such a unity of plan among all the animals which have backbones, and which we technically call Vertebrata. But there are multitudes of other animals, such as crabs, lobsters, spiders, and so on, which we term Annulosa.
In the annulosa it is not distinct, although we must also remember that insects do produce enormous ravages and annoyance in many parts of the earth. It comes to a kind of climax in the ferae and raptores, which fulfil the function of butchers among land animals. As we descend through tribes, families, genera, species, it becomes fainter and fainter, but never altogether vanishes.
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