415 



Pecten, 257. 259. 387, 388. 



Pectinibranchia, comprehend Tro. 

 chus, Turbo, and many univalve 

 marine Testacea, 25. 55. 185. 



Pectunculus, ,'383. 



Pedipes, 208. 344. 



Pedicular! a, 2-iO. 245. 357. 



Pedum, 3S8. 



Periwinkle, 27. Food of the, 33. 



Perna, 385. 



Persicola, 133. 323.- 



Petricola, 257. 376. 



Phakellopleura, 358. 



Phasianella, 207. 213. 354. 



Pholadomya, 36:3. 



Pholas, its residence, 32. Power of 

 enlargingtheircave in rocks, &c., 

 32. 257. Of Linnjeus, 363. 



Pholid^, 257. 362. 



Pholidsea,, 364. 



Phyllidea and Diphyllidea, 25. 58. 

 248. 250. 358. 



Phvllidinffi, sub-family, 249. 358. 



PhvUonotus, 296. 



Physa, 187. 336. 



Phytophaga, Lamarck's subdivi- 

 sions of, 24. Food of phyto- 

 phagous gastropods, 33. 55. Or- 

 ganisation of, 56. Sexes, 56. Re- 

 spiration, 56. Confines of, with 



' the Zoophaga, 59. Point of union 

 with Zoophaga, 158. Primary 

 divisions of the phytophagous 

 shelUfish, 158. Families of, 160. 



Picidae, 262. 



Pileolus, 347. 



Pileopsis, 357. 



Pinnse, or wing-shells, 51. 387. 

 Byssus, or silken tuft of, 32. 



Pirena, 156, 157. 



Pithohelix, 164, 165. 



Piacuna, 389, 390. 



Placunomia, 390 



Plagiostoma, 388. 



Planariie, the, possess no branchia, 

 28. Form of, 37. Analogy of 

 naked slugs with, 4;! Fossil, 196. 



Planaridje. true, swim freely, 46. 



Planaxis, 59. 198. 342. Animal of, 

 204. 



Planorbis, 55. 164. 186. 227. 337. 

 P. corneus, 187. Z 



Plant-like animals, 4. n. 5. 



Pieurobranchsena, 361. 



Pleurobranchinaa, sub-family, 361. 



Pleurobranchus, 248. 252. 361. 



Pleuronectia, 388. 



Pleurotoma, 136. 1.54. 314. 



Pleurotomaria;, 213. 223. 3.53. 



Pleurotomina?, or slit-shells, 1,37. 

 152. ,314. Affinities of. 154 Cu- 

 rious analogies of, 155, 156. 



Plicadoinus, 3,32. 



Plicatclla, 78. .304. 



Plicatula, 389. 



Poll, investigations of, 16. 



Polydontes, 329. 



Polygyra, 3,30. 



Polypes, or Arcita,4. Polypes char- 

 nues, 6. Tunicated, 6. 



Polytropa, 80. P. crispata, 81. 

 Structure described, 305. 



Porcina, 104. 



Potadoma, 199.200. 341. 



Potomida, genus, 137. 276. 281.316. 



ii379. P. corrugata, 281, 282. P. 

 elongata, 282. P. littoralis, 282. 

 289. P. Batava and Sicula, 282. 



Potomis, 156. 1.58. 315. 



Potomophila, 188. 338. 



Priapulis, 6. 



Processes for capturing prey, 34. 

 Of the Nudibranchia, 37. 



Progression or locomotion of shell- 

 fish, 30. 134. 



Psammobia, 259. 370. 



Pseudoliva, 82. 306. Ps. plumbea, 

 133. 



Psittacidc-e, 262. 



Pterocera, typical of the Strom, 

 binae, 138. 310. P. lambis, 1,38. 

 P. millipeda, 138. P. sinuata, 138. 

 Analogy of the types of form of 

 the genus, 144. P. latissimus, 144. 



Pteronotus, 296. 



Pteropoda, of Lamarck, 23. Of 

 Cuvier, 25. No apparent head 

 or eyes, 3.3. First tribe of Cepha- 

 lopoda, 48. 



Ptilota, eminently typical, 51. 



Pulmonaria, 25. .55. '2uS. 



Pulvinites, 385. 



Puncticulis, 311. 



Pupa, inquiry into pupaceous shells, 

 161. 163. Description of, 164. Cy- 

 lindrical, maggot-shaped, 167. 183. 

 332. The sub-genera, 168. Ana- 

 logy of Cvclostoma to, 169. ; of 

 Clausilia with, 184. 



Pupella, 183. 334. 



Purpura, 63. 74. 204. P. lapillus, 

 and imbriratus, 80. P. coronata, 

 301. 



Purpurinae, or pur|)uras, 63. 300. 

 How far resembling Buccininje, 

 71. Analogies of Pvrulinae and, 

 73. Affinities, 95. 2(J4. 



Pusia, 320. 



Pusiodon, Sw , 3,30. 



Pusiostoma, 150. 1.52. 220. 313. 



Pustularia, 3'-'4. 



Pyramidoa, 225. 3.50. 



Pyramidella, 343. 



Pyrella spirilla, 77. 304. 



Pyrena, 315. 



Pyrula of modern authors, 83. lu 

 shape, 84. P. perversa, 84 P. 

 mvristica, 86 P. hippocastanum, 



86. P. lineata, 86. P. carnaria, 



87. Characters of, 307. 



