Beads made from the columell of univalves have generally a number of distinguishing characteristics.
The first two include univalves and Bivalves, the last only univalves.
The former are univalves and the latter bivalves having two shells for protection.
Yet, since each of these three univalves has been this day created, these inferences are deceptive.
Hermit Crabs take possession of the deserted shells of the univalves, and crawl in pursuit of garbage along the moist beach.
Care should be taken not to injure the edge or lip of the mouth of univalves, or the ligament of the hinge of bivalves.
We believed the univalves had been chiefly described by him; one, or probably two of the species were not contained in his memoir.
The univalves which possess a siphon are, for the most part, carnivorous, and are often most voracious creatures.
A few of the univalves are viviparous—that is, they produce their young alive; but the majority lay eggs.
Most species of univalves are wanderers, many bivalves are free, and multivalves become fixed at an early stage of existence.
A gastropod, especially one with a single shell, such as a snail, cone, whelk, abalone, or limpet. Univalves belong to the subclass Prosobranchia. Their shells are usually spiral and can hold the whole animal inside. Compare bivalve.