248 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
hardly any trace of lateral areas; sculpture of the valves nearly uniform, 
fine, equal grooves, axially on the dorsal area, oblique on the lateral areas 
and cut by still finer transverse striae into microscopic granulations; the 
distal ends of the middle valves in the adult shell with concentric undu¬ 
lations; insertion plates short, entire; girdle with crowded arenaceous, 
short spinules, interspaced near the valve margins with sparse longer white 
spines, the body of the girdle partaking of the colors of the shell, with a 
silvery reflection in certain aspects; extreme edge of the eaves finely 
striated in accordance with the exterior sculpture; interior whitish, the 
jugal sinus obscure, the sutural laminae narrow, arcuate, widely separated; 
a conspicuous median excavation bordered behind by two wing-like, radi- 
ately grooved, narrow callosities on the internal face of the valve under 
the central area of the posterior valve. Length of valves, 17; width, 8; 
height, 3 mm. (Dali.) 
Type in United States National Museum, No. 274120. Type locality, 
Santa Barbara Channel in 20-40 fathoms. 
Range. Known only from type locality. 
Lepidopleurus lycurgus Dali, 1919 
Proceedings of the United States National Museum, 55:500. 
Chiton minute, white, with touches of brown on either side of the 
jugal area; dorsum rather angular with flattened sides; anterior valve less 
than semicircular, its edge excavated behind, simple; posterior valve 
axially longer, with a prominent smooth subcentral mucro over a concave 
posterior slope; central area axially grooved, minutely granulose; posterior 
area with radial granulose very minute sculpture; intermediate valves with 
no marked jugal area, that and the pleural tracts with oblique minute 
reticulations; lateral areas distinct, radially minutely striate-punctate, with 
some obscure concentric undulations distally; girdle spiculose with minute 
white spinules of uneven length; interior white. Length of valves, 4.5; 
width, 3; height, 1 mm. (Dali.) 
Type in United States National Museum, No. 274119. Type locality, 
Catalina Island, California. 
Range. Known only from type locality. 
Lepidopleurus oldroydi (Bartsch) Dali, 1919 
Proceedings of the United States National Museum, 55:500. 
Chiton white, with a blackish spot on either side of the jugal area, 
strongly sculptured; back moderately arcuate, anterior valve semicircular, 
sculptured with irregularly disposed, small, prominent, round pustules; 
f 8501 
