Lectures on Mollusca: Or, "Shell-fish" and Their Allies

abound Ammonites animal apex appear arms beaks beautiful Berkeley bivalves body breathing pipe burrowing byssus CALIFORNIA LIBRARY canal cartilage cavity Cephalopods Chitons closed Cockles Cowries crawl Crawlers creatures cretaceous curious cuttles Eocene eyes Family flaps flat flattened fold foot fossil found fossil fringed front Gasteropods genera genus gills grooved head Heteropods hinge teeth hole horny keeled known Lamarck lateral teeth layer ligament Limpets living mantle mantle-bend many-whirled mollusks mouth Muricids Natica Nautilus nearly notch Nudibranchs numerous oolitic operculum ordinary organs outer lip oysters peculiar Periwinkles pillar lip plaits plates proboscis Pteropods resembles rocks round rows sand Scalaria sculptured Sea-hares seas shape shell shores short siphon siphuncle skin slender slit snails snout sometimes species spiral spire stout strata Strombs suture swimming tail tentacles tertiary thin tooth tribe tropical America true tube twisted typical umbilicus UNIVERSITY OF CALIFORNIA valves varices Whelks whirls