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Rh fly-shaped valves are completely covered by the large, leathery, firm girdle which is reddish brown to yellowish brown. Minute red spicules make the girdle feel gritty. Common in the northern part of its range. Formerly called Cryptochiton stelleri.

Figure 67. Atlantic Coast chitons, showing from the underside the position and length of gills and the nature of the lappets, a, Ceratozona nigosa Sby., i to 2 inches; b, Cryptoconchns floridaniis Dall, i inch; c, Calloplax jajieirejisis Gray, % inch; d, Chaetopleura apiculata Say, % inch; e, Tojiicia schranmti Shuttleworth, I inch; f, Chitoji tuber ciilata Linne, 3 inches. Family ISCHNOCHITONIDAE Genus Calloplax Thiele 1909 Rio Janeiro Chiton Figure 67c Calloplax janeirensis Gray Lower Florida Keys and the West Indies. Brazil. % to % inch in length, oblong, gray to greenish brown, or speckled with red. Very strongly sculptured. Lateral areas strongly elevated by 3 to 4 very coarse, large, beaded ribs; anterior valve with 12 to 18 such ribs. Central ridge (or jugal tract) with longitudinal rows of fine beads; apex elevated, smooth and rounded. Central area with about 1 2 very sharp, gran- ulose, longitudinal ribs. Interior white. Anterior valve with i o, middle valves with I and posterior valve with 9 slits. Girdle with very fine "sugary" scales and an occasional single hair. Gills start Ys the way back from the head and extend posteriorly to a large, fleshy lappet on the posterior margin of the girdle. An uncommon species. Genus Chaetopleura Shuttleworth 1853 Chaetopleura apiculata Say Common Eastern Chiton Figures 6-jd 68 Cape Cod, Massachusetts, to both sides of Florida. % to % inch in length, oblong to oval. Valves slightly carinate. Central