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ISCHNOCHITONIDAE 3 2 3
I to 1V2 inches in length, rather oval in shape. Color variable: com-
monly yellowish with dark reddish brown streaks and maculations. Central
areas with strong, longitudinal ribs and smaller, lower cross ridges which
give a netted appearance. Jugal area V-shaped and with 5 to 6 smooth longi-
tudinal ribs. Lateral areas raised, smoothish and with a few prominent warts.
Anterior valves with 30 or more radial rows of warts which are largest
near the girdle. Interior whitish, or rarely tinged with pink. Girdle with al-
ternating yellowish and reddish bands; covered with tiny, low, smooth, split-
pea scales. Very abundant just offshore, especially in the northern part of
its range.
Iscknochiton californiensis Berry Trellised Chiton
Southern California to Lower California.
I to 1% inches in length, oval to oblong, heavily sculptured. Color a
dull-greenish with yellowish splotches and with a dark-brown area on the
top of each valve. Central area with longitudinal and cross ribs which give a
strong netted appearance. Lateral areas raised and with 4 rows of prominent
beads. Posterior edge of valves serrated with about 20 small tooth-shaped
beads. Anterior valve with 20 to 27 strongly granular ribs. Girdle closely
packed with convex, tiny, split-pea scales. Moderately common and for-
merly thought to be /. clathratus Reeve which, however, is only from the
Panamic Province to the south.
Ischnochiton cooperi Pilsbry Cooper's Chiton
Southern California.
I to 1% inches in length, rather oval in shape. Color olive-green to
olive-brown and clouded with light-blue. Central area with closely packed,
sharp, longitudinal ribs which are finely striated. Jugal area with the same
type of ribs and with its anterior end having about 10 notches. Lateral areas
raised and with 4 to 8 irregular rows of prominent, rounded warts.
Interior of valves bluish. Girdle covered with tiny, flat, striated, split-pea
scales. Uncommon.
Ischnochiton palmulatiis Pilsbry Big-end Chiton
Southern California.
% inch in length, oblong and with the posterior valve massive and
greatly swollen. Color of valves yellowish brown to light grayish green
with dark blackish green in the areas just above the girdle. Central areas
carinate at the top, with 20 to 30 strong, rounded, longitudinal ribs. Lateral