296 University of California Publications in Zoology (Vou. 14 
Interior light blue, with darker stains at bases of the sutural laminae and 
behind the rather strong blue white valve callus. Sinus and sutural laminae as 
in hartwegii. Slits in valve i, 8; valves ii-vii, 1-1; valve viii, 11; teeth of end 
valves blunt, thick, but not distinctly bilobed. All teeth longer than the narrow, 
porous eaves. 
Girdle narrow, black or with small whitish spots, leathery, very minutely 
papillose.’’ 
A single small specimen was obtained by the Survey from Bonita 
Point. This species has not hitherto been reported from this region. 
Range.—Victoria, B. C., to Monterey, California. 
MOPALIIDAE 
Mopalia Gray 
Mopalia ciliata Sowerby 
Chiton ciliatus Sowerby (1840), p. 289. 
Mopalia ciliata, Wood and Raymond (1891), p. 58; Pilsbry Cee 
p. 303, pl. 64, figs. 64-73; Arnold, R. (1903), p. 343. 
Description—Pilsbry (1892) desea’ this species as follows: 
‘‘Shell oblong, rather depressed, the dorsal ridge carinated (sometimes 
rounded), side-slopes straight or somewhat convex. Surface lusterless, finely 
sculptured, variously colored, usually either (1, typical coloring) verdigris 
green maculated with black or black-brown, the girdle yellow or (2) maculated 
with maroon and sometimes touched with rich chestnut on the ridge, or having 
some valves or parts of valves vivid scarlet, or scarlet mixed with olive and 
snow-white, or entirely white; or (3) light olive-buff with brownish girdle. 
Valves somewhat beaked, the lateral areas bounded by a riblet, rather 
coarsely granulated, with larger granules along the posterior margin. Central 
areas sculptured with longitudinal, curving riblets somewhat granulated, much 
closer and finer on the dorsal ridge. Anterior valve having granose narrow 
radii, the intervals granulated. Posterior valve small, with posterior mucro, 
broadly emarginate or waved at the hinder margin. 
Interior bluish-white or light blue-green. Sinus broad and rather rounded, 
spongy or roughened. Sutural plates arcuate. Anterior valve having 8 slits, 
median yalves 1 slit. Posterior valve having a broad deep, rounded caudal 
sinus, and a single slit on each side. 
Girdle wide, yellow or brown, generally notched behind, more or less sparsely 
clothed with curling strap-like brown hairs, which bear near their bases a 
bunch of minute, white, acute spines.’’ 
Length, 7 to 20 mm. 
Occurrence.—At stations D 5755 (2), D4774t (1), D 5809 (3), and 
questionably at D 5775. 
This chiton was taken alive by the Survey only within the middle 
division of the bay at depths ranging from 314 to 53 fathoms and 
from bottoms that were predominantly gravelly or stony. 
Range—Shumagin Islands, Alaska, to San Diego, California 
(Oreutt). 
