Por"pi*ta (?), n. [NL., from Gr. brooch.] Zool.
A genus of bright-colored Siphonophora found floating in the warmer parts of the ocean. The individuals are round and disk-shaped, with a large zooid in the center of the under side, surrounded by smaller nutritive and reproductive zooids, and by slender dactylozooids near the margin. The disk contains a central float, or pneumatocyst.
© Webster 1913.