CLASS GASTROPODA 
279 
Ischnochiton corrugatus Carpenter, 1892 
Tryon and Pilsbry, Manual of Conchology, 14:123. 
Shell similar to C. sanguineus in form and varied coloring; entire sur¬ 
face granulose; central areas having impressed punctate wrinkles, hardly 
lirate; lateral areas strongly longitudinally corrugated. Interior: posterior 
valve with 8-10, anterior valve 10-9, central valves 1 slit. Sinus wide, 
flat. Girdle thin, covered with very close, very small striatulate imbricating 
scales. Length, 13j4; breadth, 7 mm.; divergence, 90°-100°. (Pilsbry.) 
Type in California State Collection. Type locality, Catalina Island, 
California. 
Range. Catalina Island, California, to Todos Santos Bay, Lower Cali¬ 
fornia. 
Ischnochiton berryi Dali, 1919 
Proceedings of the United States National Museum, 55:507. 
Chiton of moderate size, deep crimson with irregular blotches of brown 
and white on its lateral slopes, and a crimson girdle of rounded, densely 
imbricated small scales; gill rows ambient; anterior valve with a nearly 
smooth mucro, from which radiate about 20 more or less corrugated, 
sometimes bifurcating threads, the whole overspread like the rest of the 
shell by an almost microscopic decussation; anterior slits about 12; pos¬ 
terior valve much smaller with a subcentral mucro, from which radiate 
threads, like those on the anterior valve, in all directions; posterior slits 
11; intermediate valves with one slit, jugal area minutely decussated, 
almost carinate; lateral areas with usually three corrugated ribs, the nodu- 
lation of the posterior rib undulating the margin of the valve, but there 
may be one or two minor intercalary ribs; the pleural areas are axially 
ribbed with deep decussated interspaces, the ribs growing stronger as they 
recede from the jugal region; interior pink, the jugal sinus hardly marked, 
axially striated, merging laterally into narrow sutural laminae. Length of 
shell, 11; width, 7; height, 2.5 mm. (Dali.) 
Type in United States National Museum, No. 193375. Type locality, 
Pacific Grove, California. 
Range. Monterey to San Pedro, California. 
SECTION LEPIDOZONA Pilsbry, 1892 
Ischnochiton willetti Berry, 1917 
Proceedings of the California Academy of Sciences , series 4, 7:236, figs. 1, 2. 
Shell rather large, regularly elliptical; elevated, with an angular dorsal 
ridge and arculate side slopes. General surface indistinctly granulose. 
[881] 
