INDEX 
Progression, mode of, 115 
Prolecanites Henslowi, xxii, 
Pyroneomenia Sluiteri, ix. 
Proéstracum, 40. 
Propodium, 116 
Prosobranchia, 23 
Prosogyre, 30 
Protective coloration, 119-121 
Protobranchia, 34 
Protoconch, 19, 94 
Psammobia, 108 
Psammobia squamosa, xix, 
Psammobia vespertina, xv, 
Pseudomilax, 106 
Psyche globulosa, xxvi. 
Ptevia, 9, 74, 132, 133 
Ptevia hivundo, xvii. 
Pteriidez, 109 
Ptevocera, 63, 97, 104, 117 
Pterocera lambis, v. 
Pteropoda (Sea-Butterflies), 56, 
105, 117, 132 
Pulmonata, 10, 25, 126, 130 
Puncturella noachina, ix, 
Pupidez = Pupillidz 
Pupillidz, 47, 88, 123 
Pupina bicanaliculata, x. 
Purple Sea Snail. See Ianthina. 
Purpura (Dog-Periwinkle), 54, 
68, 89, 104, 143 
Purpura lapillus, go 
Pyvamidula, 47, 88 
Pythia plicata, viii. 
Radiolitidz, 49 
Radula, 6, 9, 10, 125-127 
Rangiide, 58 
Razor Fish. See Ensis. i 
Relationships of the Mollusca, 13 
Reproduction, 87 
Reproduction of lost parts, 135 
Resemblances in external form, 
134 
Respiratory System, 7, 128 
Rhachidian tooth, 12 
Rhachiglossa, 24, 125 
Rhaphistoma, 44 
Rhipidoglossa, 24, 125, 132 
Rhizochilus, 68, 81, 97 
155 
Rhizochilus antipathicus, xi. 
Rimula, 95 
Rimula exquisita, vii. 
Ringicula vingens, v. 
Rissoia costata, Embryo, xxix. 
Robillavdia, 81 
Rocellavi dubia, xix. 
Roman Snail. See Helix po- 
matia, 
Rongo, 142 
Rossia, 75) 
Rostellavia, 63, 97, 117 
Rostellavia curta, x. 
Rudistes, 106 
Rumina decollata, 21, 70, vii., xiii. 
Sagda Cookiana, xiii. 
Salt-water, Fresh-water Molluscs 
in, 53 
Sanguinolavia, 64 
Saxicava, 54, 61, 119 
Saxicava rugosa, xix. 
Saxicavide, 49 
Saxidomus, 142 
Scalavia=Epitonium 
Scalites, 45 
Scallop. See Pecten. 
Scaphander, 69 
Scaphandeyr lignarius, xii. 
Scaphander lignavius : gizzard, iti, 
Scaphites, 38 
Scaphites equalis, xxii. 
Scaphopoda, 25, 51, 69, 106, 127 
Scaphula pinna, 57 
Scars of Muscle attachments, 33 
Scenella, 44 
Schizodentalium, 26 
Schizodentalium plurifissuratum, 95 
Scioberetia, 80, 109 
Scissuvella, 129 
Scissurella crispata, vii. 
Scrobiculavia, 57, 108 
Sculpturing, 5 
Scyllea pelagica, xii. 
Sea-Butterflies. See Pteropoda. 
Sea-Hare, See Aplysia. 
Sea-Slugs. See Nudibranchia. 
Seasonal changes, effect of, 72,73 
Sense organs, 8 
