Similar animalcules to the above, but with a body strongly annulated, naked or covered with a double shell, and provided with numerous feet, unto which are attached leaflets that serve as branchiæ.
Here belong the Branchiopoda properly so called.
Fam. 3. Cardiaceoid, Shield-Crabs.
Large animals, with strongly annulated body and numerous feet; head and back covered by a shield, whereupon are the eyes—Phyllopoda.
Here range the Trilobites, Apus, and the Molucca or King-Crabs.
Order 2. Spaltmuschelartige, Scheerenkrebse.
3510. Five pairs of thoracic feet, of which the first pair is mostly large and forcipiform; the eyes upon moveable pedicles or foot-stalks.
These animals usually attain a striking size, and are generally the largest among the horny Ancyliozoa.
The sexual parts open mostly upon the posterior legs.
The abdomen or tail usually supports five pairs of stunted feet, to which the ova hang.