290 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
a thickened sheath-like base from which are given off slender, more or less 
recurved, hair-like processes. All together there are 22 of these tufts 
besides an equal or slightly larger number of minor (alternating) ones. 
The typical form seems to be pink with sutural spots of brown and more 
or less green suffusion. The girdle shows alternating bands of burnt sienna 
and pale buff. The latter are sutural in position and there are also small 
intersutural spots of the same color. The interior is rose, paler toward the 
edges, but not so vivid as in M. heat hi. Length, 9; width, 5 mm. (Berry.) 
Type in Berry Collection. Type locality, off Monterey, California. 
Range. Resurrection Bay, Alaska, to San Martin Island, Lower Cali¬ 
fornia. 
Chaetopleura gothica Carpenter, 1864 
Supplementary Report, British Association for the Advancement of Science, 649. 
Tryon and Pilsbry, Manual of Conchology, 14:74 and 15:65; PI. 15, figs. 28, 29. 
Blunt parallel riblets along very arched back. Sutural lobes united at 
sinus; eaves not spongy. 8-20 fm. (Carpenter.) 
Shell small, much elevated, green, elegantly tinted with rose and olive; 
valves gothic-arched, the dorsal ridge acute; lateral areas small, arcuately 
distinctly defined, granulose; umbones prominent; umbonal margin having 
a tessellated color pattern and incurved. Central areas longitudinally 
ribbed, ribs rounded, close, not much elevated, the interstices small, some¬ 
times slightly decussated. End valves sculptured like the lateral areas, the 
tail valve having the umbo median and somewhat elevated. Interior having 
the sutural plates scarcely separated, the jugal sinus very broad and 
shallow; insertion plates of median valves having a single slit, terminal 
plates with 8-10 slits; the plates are obtuse; eaves hardly elevated. Girdle 
most minutely scaly, the granules very close, rounded, smooth; edge with 
small suberect hairs. (Carpenter.) Length, 5; breadth, 2j4 mm.; div., 80°. 
(Tryon and Pilsbry, Manual of Conchology .) 
Type in United States National Museum. Type locality, Catalina 
Island, California. 
Range. Monterey to Catalina Island, California. 
Described as Trachydernion Gothicus Carpenter. 
Genus PALLOCHITON Dali, 1878 
Valves exposed, solid, the anterior and median having sharp insertion 
teeth slightly roughened outside; slits of anterior valve not corresponding 
to anything in the external sculpture; tail valve having the mucro at the 
posterior end, the teeth sharp and all strongly directed forward; eaves 
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