Fig. 10. Transmission electron micrographs of the iridophores in the arm stripes of the squid (L. pealeii) (A) and the cuttlefish (S. officinalis) (B). Sections were cut perpendicular to the longitudinal axis of the arm. The arrow in each graph indicates the direction toward the nearest skin surface. C, pigment granules of a chromatophore. Scale bars, 7.5 µm.