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American Seashells

is concave. Girdle very narrow, same color as the valves, and with very minute, gritty granules. L. (C.) dentiens is a common intertidal form found north of Monterey County, California. It is replaced to the south by the very similar and common L. (L.) keepiana Berry (Keep's Baby Chiton). In the former, the insertion teeth are prominently developed, their bounding slits in general widely V-shaped, and the teeth of the posterior valve very acute on the sides; the eaves are wide and conspicuously porous or "spongy." In the latter species, there are numerous short, fiarroivly slitted teeth in the terminal valves, and extremely thin, narrow, less openly porous eaves. (See S. S. Berry, 1948, Leaflets in Malacology, vol. i, no. 4.) Lepidochitoiia hart^uegi Carpenter ' Hartweg's Baby Chiton Washington to Lower California. I to 1 34 inches in length, oval, rather flattened. Similarly colored to L. de?itiens. Girdle narrow and finely granulated. Sculpture of the end valves and the lateral areas of the middle valves differs from the microscopic granu- lations of dentiens in bearing easily seen, but very tiny, warts. It also differs in having the area behind the apex of the posterior valve convex instead of concave. Moderately common in intertidal areas. Genus Nuttallina Carpenter 1879 Nuttallina californica Reeve Californian Nuttall Chiton Vancouver Island to San Diego, California. About I inch in length, almost 3 times as long as wide. Color dark- brown to olive-brown. Upper surface of valves finely granulated and with a shallow furrow on each side of the smooth dorsal ridge. Apex, or mucro, of posterior valve so far back that it extends beyond the posterior margin of the eaves. Interior of valves bluish. Posterior valve about as wide as long and with 8 to 9 slits. Girdle with short, rigid spinelets mostly brown in color and with a few white ones intermingled. The girdle looks mossy. Moderately common. Nuttallina scahra Reeve Rough Nuttall Chiton San Diego to Lower California. Very similar to N. californica, but the posterior valve twice as wide as long. Color of valves lighter. Girdle spines much less numerous. This is Carpenter's Acanthopleura flexa.