338 INDEX 



Page 



Plants helopliytes 38 39 



hydrophytes 37 



jack pine association 4g 49 



barrens 52 



juncus association 3g 49 



mesophytes 44 



mesophytic woods 23 



phragmites association 40 



poa association 4g 



potamogeton association 38 



psammophytes 45 



phytogeograpliical relations 58, 71 



quadrats 39, 55 



reed swamp formation 40 



scirpus association 38, 40 



species of 72 



succession of 36, 54 



water-lily association 37, 38 



wooded swamp formation 43 



xerophytes 38, 39 



xerophytic society 21 



Plargyrus americanus 249 



Plethodon cinereus 23, 258, 260, 261 



Pleurocera subulare intensum 135, 169, 170 



Pleuroceridae 169 



Pluteus cervinus 56 



Poa annua 79 



compressa 49, 53, 79 



pratensis 45, 79, 182, 186, 208, 209, 210, 211 



triflora 79 



Podilymbus podiceps 30, 275, 276 



Podophyllum peltatum 94 



Polioptila caerulea 275, 306 



Polygala paucifolia _. 101 



polygama 101 



senega 101 



Polygonatum biflorum 85 



commutatum 51, 86 



Polygonella articulata 91 



Polygonum acre 91 



amphibium 41, 90, 209, 212 



hartwright ii 90 



aviculare 90 



cilinode 91 



convolvulus 91 



erectum 90 



hydropiper 41,91 



hydropiperoides 41 , 91 



lapathifolium 90 



muhlenbergii 90 



orientale 91 



pennsylvanicum 91 



persicaria 41, 42, 91 



scandens 91 



virginianum 91 



Polygyra albolabris " 142, 143, 144, 145, 146, 147, 148, 149, 153 



albolabris dentata 143, 153 



maratima 21,142,144,148,149,153 



fraterna. 144, 148, 149, 154 



nionodon 142, 143, 145, 146, 147, 149, 154 



multiUneata 143, 145, 146, 153 



thyroides 143, 145, 146, 147, 148, 149, 154 



Folypodium vulgare .- 31, 68, 72 



