[40]. “Old Red Sandstone,” pp. 41, 42.
[41]. “Old Red Sandstone,” p. 69.
[42]. From akanthos, a thorn, and pterugion, the fin.
[43]. From malakos, soft, and pterugion, the fin.
[44]. 1. Ganoid, from ganos, splendour, because the scales are coated with a bright enamel.
[45]. 2. Placoid, from plax, a plate; sometimes large, sometimes reduced to a point; e.g. shark.
[46]. 3. Ctenoid, from kteis (gen. ktenos, a comb); scales jagged like a comb.
[47]. 4. Cycloid, from kuklos, a circle; scales smooth and simple: e.g. salmon, &c.
[48]. From kephalē, the head; aspis, a buckler.
[49]. Coccosteus, from kokkos, a berry, and osteon, a bone.