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464 common. John Q. Burch reports that the siphons have characteristic tubercles on their surface. Siphon cream, covered with a brownish periostracum at the base, the remainder studded with small bars of chitinous material, thus giving a warty appearance. Genus Nettastoviella Carpenter 1865 Nettastomella rostrata Valenciennes Rostrate Piddock Puget Sound to San Diego, California. % inch in length, with a very large, oval gape posteriorly, and anteriorly with a long, pointed, smooth rostrum or snout which bends downward. Shell proper with widely spaced, delicate, high, concentric lamellae. With- out accessory plates and apophyses. Found by breaking stones apart. Mod- erately common. Genus Parapholas Conrad 1849 Farapholas californica Conrad Scale-sided Piddock Southern California. 3 to 5 inches in length, oval-oblong, rotund, especially anteriorly. Pos- terior round in cross-section and gaping. Dorsal margin with 2 long, com- plicated, accessory plates. Ventral edge covered by one elongate plate. Anterior gape closed over by 2 thin, eggshell-like extensions. Sides of snout with foliated periostracum. Shell proper with a long, radial groove pushing in at the middle. Color grayish white. Interior with 2 long, descending, shelly rods under the middle of the hinge. Common. Genus Nave a Gray 1851 Navea subglobosa Gray Abalone Borer San Pedro to Monterey, California. /4 to % inch in size. Very obese and subglobular. Anterior end widely gaping with the thick edge of the valves coarsely denticulate. Commonly found boring in abalone shells (Haliotis). Genus Martesia Blainvillc 1824 Martesia striata Linne Striate Martesia Plate 32W West Florida to Texas and the West Indies.