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ISCHNOCHITONIDAE 319
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,
Calloplax janeirensis Gray
I inch; f, Chitoji tuberciilata Linne, 3 inches.
Family ISCHNOCHITONIDAE
Genus Calloplax Thiele 1909
Lower Florida Keys and the West Indies. Brazil.
Rio Janeiro Chiton
Figure 67c
% 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
Cape Cod, Massachusetts, to both sides of Florida.
Figures 6-jd\ 68
% to % inch in length, oblong to oval. Valves slightly carinate. Central