133. Physa fontinalis 134. Conovulus denticulatus 135. Snail and shell of Carychium minimum 136. Ancylus fluviatilis 137. Conovulus denticulatus, var. myosotis . 143. Snail of Valvata cristata, much enlarged 144. Snail of Acme fusca, much enlarged. INDEX. Technical terms are in italics, and will be found explained A. ACHATINA ACICULA, 171; pulsations of the heart of, 172; Acme fusca, 223; how to secure, ib. Adductor muscles of bivalves, 18. Agate snails, 171. Air-breathing snails, 65; relation of, to water-breathing snails, ib.; orders of, ib. Alasmodonta margaritifera, 27. Amber snails, 174. Amphipeplea genus, 186. glutinosa, 196. involuta, 198. Amphistoma subclavatum, parasite of Cyclas, 35. Anal opening in bivalves, 14. Ancylus genus (fresh-water limpets), 205. fluviatilis, 206; respiration in, 207; parasite of, 208. lacustris, 208. oblongus, 208. Animal kingdom, primary divisions of, 1. Annulose animals, 2. Anodon anatinus, 31. cygneus, 30; varieties of, 31; mite of, 32. Anterior margin, 10. Aplexa hypnorum, 203. Arion ater, 69; parasites on, 70; internal organs of, ib. Atax ypsilophora, mite of the Swan mussel, 32. Avicula margaritifera, pearls of, 28. Azeca tridens, 152. B. BALEA PERVERSA, 164. Bithinia Leachii, 57. tentaculata, 56. Bivalves, parts of shell of, 10-13; composition and structure Branchial opening in bivalves, 14. Breadth of shell, 11. Bubble snails, 201. Bulimus genus, characters and species of, 146. acutus, 147. montanus, 148. obscurus, 149. Byssus, nature of, 21. C. CADDIS-WORM case like Valvata piscinalis, 59. Cardinal teeth, 12. Carychium minimum, 177. exiguum, 178. Chrysalis snails, 152. Circulatory system of bivalves, 15 ; in univalves, 52. |