258 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
Type in Academy of Sciences, St. Petersburg. Type locality, Patria: 
Insula Sitka. 
Range. Known only from type locality. 
Described as Chiton sitkensis. 
SECTION LEPIDOCHITONA s.s. 
Lepidochitona alba Linnaeus, 1767 
Systema Naturae, 12th ed., 1107. Tryon and Pilsbry, Manual of Conchology, 14:70; 
PI. 7, figs. 35-38. 
C. testa octovali laevi; valvula prima postice enmarginata. Testa ovalis, 
laevis, alba, vix dorsata, minus caruhata. (Linnaeus.) 
Shell oblong, elevated, the back keeled, lateral slopes nearly straight. 
Anterior valve half-circular, its posterior margin slightly concave; sculp¬ 
ture consisting of some scarcely perceptible, low radiating ridges, often 
wholly obsolete, and an excessively minute shangreening or granulation of 
the whole surface, the granules showing a disposition to be arranged in 
oblique curved lines. Intermediate valves slightly beaked, produced for¬ 
ward in the middle, having the same sculpture, and showing low, irregular 
growth wrinkles. Lateral areas scarcely raised, sculptured like the front 
valve. Posterior valve having the umbo slightly elevated, central, inclined 
backward. Interior white. Sutural plates large and wide, extending from 
the insertion plates nearly to the jugum. Sinus rounded. The anterior 
valve has 13 slits in the smooth and rather sharp insertion plate; the inter¬ 
mediate valves have one slit; the posterior valve has 10 slits, and the edge 
of the plate is decidedly roughened and irregular. Another specimen has 
14 slits in the anterior valve, 12 in posterior valve, and in still another 
individual, some of the intermediate valves have two slits on one side. 
The girdle is covered with small gravelly scales, and has no marginal 
fringe of long scales or spines. The color is a very delicate buff tint, some¬ 
times almost white, often shading into a light orange on the posterior part 
and lateral areas of each valve. Most of the specimens have more or less 
of a black deposit on the back part of the valves. Length, 15; breadth, 
7 mm. (Tryon and Pilsbry, Manual of Conchology.) 
Type in Linnaeus Society, London. Type locality, 0. Islandico Knoig. 
Range. Arctic Ocean to San Diego, California; Greenland, Iceland, 
Spitzbergen, Scandinavia; British Seas, Gulf of St. Lawrence, Maine, and 
south to Massachusetts Bay. 
Lepidochitona sharpei Pilsbry, 1896 
Nautilus, 10:50. 
Shell oblong, elevated, carinated, the side slopes somewhat convex. 
Surface to the naked eye smooth; lustreless; slightly soiled white, with 
[8601 
