The number of maxillæ agrees tolerably well with that of the thoracic feet.
Fam. 4. Mytiloid, Locust-Crabs.
All the feet of pretty equal length, and the forceps stunted in size; the branchial plates free upon the abdominal feet—Squilla.
Fam. 5. Arcaceous, Macroura.
Abdominal feet arrested, branchial comb upon the femora of the thoracic feet and beneath the dorsal shield, tail extended, as in the common Cray-fish.
Fam. 6. Oyster-like Crustacea, Brachyura.
Characters similar, but tail bent under the body—Taschenkrebse.
COHORT II. SNAIL-LIKE CRUSTACEA—ASSELN.
3511. Body mostly cylindrical, annulate, without a true carapax or scute; head free; feet short and simple; branchiæ vesici-or folii-form; mostly placed under the tail; eyes non-pediculated, or even wanting.
Order 3. Androgynoid—Saugasseln.