The true or proper Insects transcend the Sexual animals, and therefore conform to the classification of their own circle, namely, they repeat the Worms and Crabs, and finally mount forth upon their own stage.
The inferior or lower organized animals form consequently two series, viz. the Smooth and Annulate, which in their lower members range parallel, and that indeed after the following manner:
| A. Smooth. | B. Annulated or Ringed. | ||
| I. Protozoa. | I. Worms. | ||
| a. Stomach, | 1. Infusoria. | 1. White-blooded Worms. | |
| b. Intestine, | 2. Polypi. | 2. Red-blooded Worms. | |
| c. Absorbents, | 3. Acalephæ. | 3. Holothuriæ. | |
| II. Conchozoa. | II. Crustacea. | ||
| d. Veins, | 4. Mussels. | 4. Crabs. | |
| e. Arteries, | 5. Snails. | 5. Aselli. | |
| f. Hearts, | 6. Kracken. | 6. Spiders. | |
| III. Ancyliozoa. | III. Flies. | ||
| g. Retia, | 7. Worms. | 7. Tracheoptera. | |
| h. Branchiæ, | 8. Crabs. | 8. Dictyoptera. | |
| i. Tracheæ, | 9. Flies. | 9. Ceratoptera. | |
The Worms have simply an annulate body with reticular or filamentary branchiæ, but no feet; the branchiæ are supported by the body.
The Crabs have an annulate body with feet; the branchiæ are supported by limbs.
The Insects have an annulate body with feet and wings; the body is supported by the branchiæ.
Seventh Class.
Reticular, Papillose Animals—Worms.
Protozooid Ancyliozoa.
3503. There are Worms with a soft body and white blood, without proper tentacula; others with red blood, with and without tentacula, having also bristles along the sides of the body; lastly, the rings of the body become hard or muscular, and a circle or ring of osseous maxillæ forms around the mouth, which is usually surrounded by numerous tentacula, as in the Star-fishes and Holothuriæ, in whom the blood is nevertheless colourless.