552 



Percaand Amiurus nebulosus, food 

 of. compared, 499. 



lutea, 434t, 468t. 

 Perch, Common, 434t, 460t, 479t. 



and bull-heads, food of, com- 

 pared, 499. 



Pirate, 499*. 

 Percida?, 472t. 



Peridermium, 155, 212, 215, 218, 241. 

 Perisporiace.'e, 393. 

 Peronospora, 395, 423. 

 Phanerogamia, 11. 

 Phenacobius rairabilis and No- 

 tropis whipplei, food of, 

 compared, 500. 

 phenacobius, ^S'otropis, 137. 

 Philadelphia Academy of Nat- 

 ural Sciences, Proceedings, 

 cited, 73, 

 Phragmicoma, 51, 73, 117, 118, 124. 

 Phragmidium, 155, 160, 171, 204, 



219, 221. 

 Phragmospora, 212, 213. 

 Phryganeidfe, 442t, 469t, 4731- 



larvae, 454t, 461t. 466t, 470t, 

 485t. 

 Phyllactinia, 392, 396, 397, 411, 414. 

 Physa, 44Sti 4601, 461t, 462t, 482t. 

 Phytophthora, 423. 

 Pickerel, 434*. 



Brook, 435. 



Grass, 434. 

 picta, Mamestra, 258, 305, 320. 

 Pieris bvassicte, disease of, 267. 



rapse, disease of, 259. See Cab- 

 bage Worm, European. 

 Pike, 434t* 



Wall-eyed, 503*. 

 Pileolaria, 158, 159. 

 Pirate Perch, 499*. 

 Pisidium, 461t. 

 Placophnrynx, 440. 



carinatus, 441*, 470*. 

 Plagiochasraa, 43. 

 Plagiochila, 53, 111, 116, 118, 124. 

 Planarian worm, 463t 4891. 

 Planorbis, 443t, 450t, 464t. 



Plants, leaves of, 491t. 

 structures, 491t. 

 unicellular, 439t, 4951- See 



under Vegetation, 

 platystomus, Lepidosteus, 464* 



468*. 

 Pleoch:eta, 398. 

 Pleuranthe, 52, 90, 118. 

 Pleuroschisma, 82, 83,84, 125. 

 Pleuroxus, 4501, 4o2t, 463t. 

 Pleurozia, 125. 

 Plumatella, 442t, 450t, 452t, 458t, 



467t, 4691, 473t, 488t, 4891- 

 Podisoma, 210. 



Podosphiera, 388, 392, 397, 412. 

 Porella, 76. 



Polyodon spathula, 464*, 468*. 

 PolyodontichB, 464. 

 Polyzoa, 450t, 454, 47 If, 488t, 489t. 

 Pomoxys, 434t, 468t. 



nigromaculatus and Lepomis 



pallidus, food of, compared, 



501. 

 and Ictalurus puuctatus, food 



of, compared, 498. 

 Porifera, 473t. 

 Potamogeton, 4571, 460t, 462t, 466t, 



473t. 

 Potash, caustic, effect of, upon bac- 

 teria, 318. 

 Prairie Farmer cited, 260. 

 Preissia, 31, 33, 117. 

 Proceedings Philadelphia Acad- 

 emy Natural Sciences 



cited, 73. 

 propinquus, Cambarus, 434t. 

 Protococcus, 448t, 451. 

 Protophyta, 11. 

 Protozoa, 448t, 451t, 454t, 455t, 465, 



469t, 47 It, 473t, 4S9t. 

 Pteridophyta, 11. 

 Ptilidium, 81. 

 Puccinia, 145, 148, 155, 160, 161, 163, 



165, 170, 206, 208, 218, 221, 



2.31, 234, 235, 241. 

 Pucciniopsis, 171. 

 pulex, Daphnia, 4671- 



