Circular in cross section, the body may reach lengths of 2 to 3 cm. The paired tentacles have relatively short side branches. The equal-length comb rows extend from the aboral end part way along the length of the body, to the openings of the sheaths where the tentacles exit. Lampea can have a milky white color, or a rosy tinge with pink pigmentation in the comb rows. It has a somewhat unusual feeding preference for a ctenophore, preying exclusively on salps.
Small individuals glomb onto the bodies of salps and consume pieces, much like a parasite.
Larger individuals can engulf entire salp chains. Sometimes seen in surface waters of Monterey Bay and deeper water off Santa Barbara, Lampea is a more common sight in the Mediterranean, Atlantic Ocean, and off the coast of Japan.