268 WEST AMERICAN SHELLS 
bluish-green, and its length is from an inch to two 
inches. Good specimens may often be found in 
rocky places between tide marks, and at lowest 
water. 
Mopalia hindsu, (Sby.), Reeve, Hinds’s Chiton. 
The shell of this species is much depressed, and the 
surface is nearly smooth. The girdle has only a 
few short hairs. The color is olive, while the in- 
terior is white, with short crimson rays under the 
beaks; its length is two inches. Found in San 
Francisco Bay and middle California. By some of 
the best authorities this is considered as only a 
variety of the last species. 
Mopala lignosa, Gld., 
the Woody Chiton, Fig- 
ure 300. This fine spe- 
cies is well represented 
in the figure, which is 
that of a large speci- 
men. The valves are 
light green in color 
within, while on the 
outside they vary from 
almost white to dark 
green. They are also 
marked with narrow 
brown lines, which 
slant from the apex of 
each valve. The girdle Fig. 300 
is generally quite rough, but sometimes we find it 
nearly smooth. This species ranges from Van- 
couver Island to Monterey. It should be said that 
specimens have been found connecting this species 
