Dictionary of Ichthyology  

epibranchial = a deep cartilage bone on the upper part of the gill arch below the uppermost element, the pharyngobranchial. May occur on arches 1, 2, 3, 4 and be covered with toothed pads.

Shark skull, a = auditory capsule, b = basibranchial, c = keratobranchial, e = epibranchial, g = gill cleft, h = hyoid, hm = hyomandibula, l = labial cartilages, m = mandible (Meckel's cartilage), o = olfactory capsule, p = pharyngobranchial, pq = pterygoquadrate, r = rostrum, s = spiracle, 2, 5 = exits of second and fifth nerves, I-V = branchial arches., from Kingsley's "Textbook of Vertebrate Zoology, 1906. Photograph by Brian W. Coad.

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