154 
Pearl Oyster. See Meleagvina. 
Pearls, 5, 140, 141 
Pearls, origin of, 79 
Pecten (Scallop Shell), 34, 112, 
I19, 133 
Pecten maximus, 55 
Pecten opevculavis, 55 
Pecten varius, xv. 
Pectenacea, 133 . 
Pectinate gill, iii. 
Pectinibranchia, 24 
Pectinidz, 46 
Pectunculus=Glycimeris 
Pedal ganglia, 8 
Pediculavia, 12% 
Pedipes, 116 
Pedum spondyloides, xvii. 
Pelagia alba, xxvi, 
Pelecypoda, 26, 51, 130 
Pen-and-Ink Fishes, 42 
Periostracum, 3 
Periphery, 19 
Peristome, 19 
Periwinkle. See Litiovina. 
Perna, 63 
Petricolay pholadiformis, 134, xxxii. 
Petricolidz, 49 
Phasianella Australis, ix. 
Philine, 111 
Philine aperta, xii. 
Philobrya, 82, 92 
Philobryidz, 109 
Philomycus, 106 
Pholadella, 46 
Pholadidea, 98 
Pholadomya candida, xx. 
Pholas (Piddock), 54, 119, 133 
Pholas vivicola,57 
Phragmocone, 40 
Phyllirrhoé, 56, 10 
5 
Physa (Bubble Snail), 53, 65, - 
10 
Physa fontinalis, xiii. 
Physide, 58 
Phytia myosotis, xiii. 
Piddock, See Pholas. 
Pinna, 4, 133, 141, 142 
Pinna nobilis, xviii. 
Pinnidz, 46 
THE LIFE OF THE MOLLUSCA 
Pisidium, 59,92 
Pisidium amnicum, xv. 
Placuna placenta, 14% 
Planktomya, 119 
Planorbide, 58 
Planorbis (Flat-coiled Water 
Snail), 10, 18, 48, 53, 65, 73,90 
Planorbis corneus, xiii. 
Platyceras, 44 
Pleural ganglia, 8 
Pleurobranchida, 132 
Pleurobranchus, 131 
Pleuroceridz, 58 
Pleuvodonta crassilabris, 135 
Pleurodonta impevator, 135 
Pleuropodia, 116 
Pleuvotoma, 20 
Pleuvotoma Babylonia, vii., xii. 
Pleuvotomaria, 20, 125, 128, 129 
Pleuvotomaria Adansoniana, 144 
Pleurotomaria Anglica, vii. 
Plicatula, 64 
Pneumoderma violaceum, xxvi. 
Polita, 70, 126 
Polita cellaria (Cellar Snail), 68, 
xiii. 
Polygyva hirsuta, viii. 
Polygyva thyvoides, 78 
Polygyvatia polygyrata, xiii, 
Polyplacophra, 7, 14 
Polypus (Octopus), 36, 110 
Polypus Digueti, 91 
Polypus tuberculatus, xxv. 
Polypus tuberculatus ; mandibles, 
iii. 
Polypus vulgavis (Common Octo- 
pus), 43 
Pomatias, 77 
Pomatias elegans, 87, ii, viii. 
Pomatiidz, 60, 116 
Pond Mussel, kept many days 
out of water, 75 
Pond Snails, 58 
Poromya hyalina, xx. 
Poromyiide, 35 
Posterior Canal, 20 
Potamides, 57 
Priscochiton, 46, 102 
Prodissoconch, 30, 94 
