324 



A NATURALIST IN THE GREAT LAKES REGION 



Plankton, food of fish, 109 

 Platteville-Galena limestone 

 Polyzoan, Pectinclla magnified, 240 

 Ponds: filling of, 15, 16, 167, 232; in 



dunes, 167, 179; first type, 168, 179; 



second type, 182, 183; third type, 



179, 193, 194 



Ponds, temporary, life of, 92 

 Pondweed, Potamogeton 

 Porphyry, 74 

 Pot holes, 86 



Potsdam formation, 46, 47 

 Prairie, 179, 242, 245 

 Predatory beetle association, 150 

 Preglacial river system, 58 

 Proterozoic, 30, 31, 41 

 Puccoon, Lithospermum canescens 

 Pyrite, 72 

 Pyroxene, 72 



Quarries, 36, 37, 45 



Quartz, 68, 69, 73 



Quartzite, 40 



Queen Anne's lace, Daucus Carota 



Rabbit, wild, see Mammals 

 Railroads, routes determined by, 88 

 Rain, an erosion agent, 11,27 

 Rainfall, effect on plant distribution, 95, 



96, 97 



Rattlebox, Crotalia sagittalis 

 Rattlesnake master, Eryngium yucci- 



folium 



Rattlesnake root, Prenanthes alba 

 Ravine: clay, 4, 259; formation of, 3, 



5, 6, 261; rock, 6, 7, 263 

 Reptilia, Snakes, Turtles: 

 Aromochelys odorata, musk turtle, 



178, 239 

 Aspidonectes spinifer, soft-shelled 



turtle, 239 

 Chelydra serpentina, snapping turtle, 



240 

 Chrysemus marginata, painted turtle, 



239, 240 

 Cnemidophorasexlineatus, sand lizard, 



99, 160, 161 

 Coluber constrictor, blue racer, 161 



Graptcmys geographicus, geographic 

 turtle, 239 



Helerodon platirhinos, hog-nosed 

 snake, 162 



LeiopcUis vernalis, prairie green snake, 



2 55 

 Thamnophis radix, prairie garter 



snake, 255 



Rice, wild, Zizania aquatica 

 Richmond shale, 34, 38, 47, 52, 58 

 Rivers, action of, 3, 27 

 River bottom association, 271 

 Rock: dumps, 12 



Rocks, 68; Chicago region, 38, 43; earli- 

 est, 25, 29, 39; igneous, 73; forma- 

 tion, 17, 28, 44; metamorphic, 39, 

 40, 76; Plutonic, 73; sedimentary, 

 17, 28, 29, 70; systems of, 31, 38; 

 table of, 75; volcanic, 73 

 Rock River, 6, 54 



Rosin weed, Silphium terebinthinaceum 

 Rotifers, 288 



Rotting log association, 225 

 Rush, bog, Juncus, several species 

 Rush, spike, Eleocharis acicularis 



Sag Station, 8, 78 



St. John's-wort, Hypericttm Kalmianum 



St. Peter's sandstone, 34, 38, 46, 54 



Salt Creek, 3, 4, 83 



Sandbars, 113 



Sarsaparilla, Aralia nudicaulis 



Sawfly, 257 



Saxifrage, swamp, Saxifraga penn- 

 sylvanica 



Schist, 4.0, 76 



Sea rocket, Cakile edentula 



Seas, epicontinental, 44 



Seasonal distribution of plants, 92, 

 248 



Sedges, see Carex 

 Sedimentation, 28 

 Serpentine, 71 

 Shale, 46, 76 



