lxx THE PALEONTOLOGY OF MINNESOTA. 
Platystrophia, 454, 458. 
biforata, 455, 444, 456, 457 
var. crassa, 458. 
crassa, 458. 
dentata,”458. 
lynx, 455. 
regularis, 455. 
Plecanium sturi, 30. 
Plectambonites, 413, 410, 417. 
decipiens, 417, 414. 
gibbosa, 416, 287, 334, 414, 417, 471. 
glabra, 414. 
minnesotensis. £15, 
planissima, 414. 
plicatella, 414. 
quinquecostata, 417. 
sericea, 414, 415-417, 457. 
sordida, 414. 
transversalis, 414-416. 
var. alabamensis, 414. 
var. prolongata, 414. 
Plectorthis, 435, 433. 
plicatella, 456. 
whitfieldi, 437. 
Pleurocystites angulatus, 287. 
Pleurotomaria, 471. 
Pleurostomella, 33, 28. 
subnodosa, 33, 52. 
Polycarpee, 5. 
Polycystina, 26. 
Polycystine, 51. 
Polymorpha spherule vitree, 43. 
Polymorpha Tuberosa et Globulifera, 40. 
Polymorphina, 28, 
Polypora, 106, 109, 111, 209, 215. 
Polystomella crispa var. scapha, 48. 
Polystomelline, 48. 
Polyzoarium, 98. 
Populites, 11. 
cyclophyllus, 11, 9, 22. 
elegans, 10, 9, 22. 
gaudini, 13. 
lancastriensis, 12, 9, 22. 
litigiosus, 12, 9, 22. 
repandocrenata, 12, 
winchelli, 12, 9, 13, 22. 
Populus, 8, 3, 5, 6, 11, 19 
berggreni, 13, 9, 22. 
cordifolia, 12. 
primeva, 9, 3, 14. 
Pores, communication, 98. 
Porifera, 51, 55. 
Poritide, 94. 
Prasopora, 244, 98, 102, 103, 106, 109, 186, 216, 220, 
248, 254, 255, 257, 286, 306, 315. 
affinis, 253, 251. 
conoidea, 249, 227, 264, 284. 
contigua, 249, 220, 250. 
graye, 244. 
insularis, 261, 207, 253, 260. 
var. filmorensis, 252, 254. 
lenticularis, 253, 260. 
oculata, 252, 248%, 251. 
selwyni, 250, 348*, 253. 
simulatrix, 245, 249, 251, 254, 275, 318. 
var. orientalis, 246, 245, 248, 251. 
Preparation, methods of microscopic, 23; of chalk, 
25; of clay, 27; of shale, 26. 
Preservation, of Brachiopoda, 333; of Bryozoa, 99. 
Primary aperture, 99. 
Prinotus pristis, 81. 
Prismopora, 106, 120, 111, 145. 
Proboscina, 119, 107, 116, 120, 121. 
auloporoidea, 119, 115. 
frondosa, 119, 115. 
tumulosa, 119, 115, 120. 
Producta incurvata, 385, 386. 
rugosa, 410. 
Productella, 368. 
minneapolis, 368. 
Pronites adscendens, 378. 
Proteacesx, 5. 
Proteoides, 5. 
Protocrisina, 107, 109, 121, 207, 208. 
exigua, 207. 
Protophyllum, 21, 8. 
crednerioides, 20, 9, 22. 
integerrimum, 21, 9, 22. 
multinerve, 21. 
quadratum, 21. 
Protorthis, 377. 
Protosalvinia chicagoensis, 24, 
huronensis, 24. 
Protozoa, 28. 
Protremata, 377. 
Proutella, 106, 110. 
Prunus, 5. 
Ptwnopora, 162. 
Pterobranchia, 104. 
Ptilodictya, 165, 106, 109, 110, 145, 162-166, 167, 
167, 169, 173, 174, 176. 
acuta, 155. 
angusta, 166. 
arctispora, 263, 
bipunctata, 174. 
canadensis, 166. 
excellens, 174. 
expansa, 166. 
falciformis, 167, 165. 
fimbriata, 174. 
flagellum, 166, 164. 
gigantea, 166. 
gladiola, 166, 164. 
lanceolata, 164, 166. 
lonsdalei, 174, 173. 
maculata, 165, 
magnifica, 164, 166. 
nebulosa, 166. 
pavonia, 167, 165. 
plumaria, 166. 
punctata, 174, 
ramosa, 171, 
sulcata, 166, 
superba, 174. 
variabilis, 166, 164. 
whiteavesi, 166. 
Ptilodictyonide, 161, 102, 106, 109, 110, 162, 163, 176. 
Ptilopora, 106, 110. 
Ptiloporella, 106. 
Ptiloporina, 106, 108-110. 
