200 



Index 



Nymphula, loi, 103, 107, 109, 184, 



197, 198. 

 Nymphula maculalis, 103, 184, 197. 



Obovaria circulus, 140. 

 Odonata, 82, 92, 97, 103, 107, 109, 



138, 205. 

 CEcetis incerta, 97, loi, 103, 107, 



109, 138, 143, 184, 196. 

 CEdogonium, 70, 82, 83, 85, 92, 94, 



95, 97, loi, 103, 105, 107, 109, 



121, 130, 133, 138, 151, 169-179, 



181, 1S3, 191. 

 CEdogonium crassiusculum, 97, 



103. 

 CEdogonium crassiusculum idio- 



androsporum, 84. 

 CEdogonium crassum longum, 84, 



107, 237. 

 CEdogonium flavcscens, 84, 97. 

 CEdogonium grande, 75, 84. 

 CEdogonium augustum, 84, 97, 103. 

 CEdogonium oblongum majus, 85. 

 CEdogonium regulosum, 75, 84, 



lOI, 



CEdogonium spirale, 85, 97, 103, 



ic8. 

 CEdogonium tumidulum, 85, 103. 

 Oleron, France, 149. 

 Oligochaeta, 92, 94, 97, loi, 103, 



107, 109, 123, 132, 138, 205. 

 Oligochfete worms, 81, 99, 103, 105. 

 Orthocladius, 76, 184, 198. 

 Ortmann, 25, 194. 

 Orthocladius, 92, 97, 133, 138. 

 Oscillatoria, 81. 

 Ostracoda, 92, 97, loi, 107, 109, 



133, 138, 147, 205. 

 Ostracods, 107, 138. 

 Oyster beds, 148, 149. 



Palpomyia, 76, 94, 97, loi, 103, 



107, 109, 123, 184, 198, 199. 

 Paludestrina nickliniana, 246. 

 Parnidje, 19, 205. 

 Pclycypoda, 1^9. 

 Pcpoon, 25, 78. 

 Perca flavescens, 220, 221. 

 Perch, pike, 212. 

 Perch, yellow, 212, 220, 221. 

 Percina caprodes zebra, 221. 

 Peoria Lake, 111., 216. 



Petersen, 17-19, 21, 23, 41, 86, 89, 



91 > 99, 150, 203, 204, 207-209, 



224. 

 Philh^drus ochraceous, 76, 184, 



199. 

 Phormidium, 83. 

 Phormidium ambiguum, 83, 97. 

 Phormidium retzii, 83, 138. 

 Phormidium tenuis, 84, 138. 

 Phryganea, lOi, 184, 196. 

 Physa, 81, 99, 109, 112, 138, 146, 



154, 159, 182, 223. 

 Physa ancillaria, 173. 

 Physa billingsi, 173. 

 Physa g^'rina, 174.. 

 Phvsa heterostropha, 76, 173, 174, 



215- 

 Physa integra, 92, 94, 97, loi, 103, 



123, 127, 133, 138, 158, 173. 

 Physa niagarensis, 173. 

 Physa sayii, 172. 

 Physa warrcniana, yj, 92, 94, 95, 



97, lOi, 103, 123, 127, 133, 138, 



146, 158, 173. 

 Physidse, 205. 

 Phytoplankton, 204. 

 Pickerel, chain, 212, 215, 218, 221. 

 Pickerel-weed, 38, 40, 47, 49, 54, 



59, 63, 64, 77, 80. 

 Pieters, 53. 



Pike, common, 218, 221. 

 Pike perch, 217, 218. 

 Pilsbry, 25, 167, 1 70, 244. 

 Pimephalus notatus, 220, 221. 

 Piona, 97, loi, 107, 109, 138, 184, 



201. 

 Pisicola, 97, 184, 188. 

 Pisidium, 76, 94, 97, loi, 103, 105, 



107, 109, 120, 133, 143, 14S, 15b, 



154, 155, 164, 214. 

 Pisidium abditum, 97, loi, 109, 



133. 164. 

 Pisidium adamsi affine, 138, 164. 

 Pisidium ?equilaterale, 164. 

 Pisidium complanatum, 94, 97, lOi, 



Pisidium compresstim, 94, 97, loi, 



103, 109, 133, 164. 

 Pisidium compressum laevigattim, 



109, 164. 

 Pisidium ferrugineum, 97, lOl, 



109, 164. 



