Dictionary of Ichthyology  

branchiostegal = one of the dermal bony (or cartilaginous) struts inserting on the epihyal and/or ceratohyal and sometimes the interhyal and hypohyal, and supporting the branchiostegal membranes. Of various forms from narrow, to plate-like to hooked, with numbers varying according to phylogeny, up to 50 in Actinopterygii to none in Crossopterygii. Less preferably called branchiostegal rays because of confusion with the fin rays.

Hyoid and opercular apparatus of Gadus, B = branchiostegals, E = os entoglossum, H = hyoid, HM = hyomandibula, I = interoperculum, O = operculum, P = preoperculum, S = suboperculum, from Kingsley's "Textbook of Vertebrate Zoology, 1906. Photograph by Brian W. Coad.

Canadian Museum of Nature