Emily Dickinson Lexicon

BRAN-CHI-OS'TE-GOUS, a. [Gr. βραγχια, gills, and ςεγος, a covering.]

Having gill-covers, or covered gills, as a branchiostegous fish; covering the gills, as the branchiostegous membrane. The branchiostegi are an order of fish in the Linnæan system, the rays of whose fins are bony, but whose gill-covers are destitute of bony rays.