358 
Rail: king, 171; sora, 171; Virginia, 171. 
Rapids: communities of intermittent, 
87; formation of, 94-99. 
Rattlesnake, 167. 
Reactions: defined, 26; positive and 
negative, 26; to current, 34, QI, 95, 
IOI, 106, 107. 
Red-legged locust, 266. 
Redstart, 274, 275. 
Regulation in behavior, 29. 
Rejuvenation of streams, 108. 
Relations of communities, 308-15. 
Reptiles: economic value of, 10, 21; in 
timber and prairie, 15. 
Reptiles, scientific names: 
—Cnemidophorus 6-lineatus, 227, 252. 
—Coluber constrictor, 255. 
—Crotalus durissus, 237. 
—RHeterodon platirhinos, 255. 
—Liopeltis vernalis, 289, 299. 
—Sistrurus catenatus, 204, 289. 
—Thamnophis, 150: 
radix, 283, 288, 296. 
—Tropidonotus grahamii, 283. 
Responses, to day and night, to weather, 
to seasonal changes, 31. 
Rheotaxis: Allee on, 327; Lyon on, tor; 
of fishes, 34, 91, 92,.95, 101; of isopods, 
2; of mollusks, 106, 107; of stream 
animals, gI, Iot. 
Rivers, drowned and sluggish, 102, 103. 
Roadsides, 13, 275. 
Rotifers: 65; diurnal migration of, 77; 
of Lake Michigan, 75-77; sessile, 131. 
Rotifers, scientific names: 
—Dinocharis tetractis, 84. 
—WNotops: 
pelagicus, 706. 
pygmaeus, 77. 
—Rotifer elongatus, 84. 
Roundworms, in Lake Michigan, 77. 
Salamanders: four-toed, 237; spotted, 
149, 278, 282, 296; sticky, 181, 183, 
207; red-backed, 197, 243, 255- 
Sandpiper, spotted, 180, 18r. 
Scorpion-flies, 202. 
Scorpion-flies, scientific names: 
—Bittacus, 202: é 
strigosus, 208. 
—Panor pa, 40, 191: 
Venosa, 200, 208. 
Seasons: Relation of animals to, 31; 
succession with, 36, 278; quantity of 
plankton in, 67. 
ANIMAL COMMUNITIES 
Sediment, in water, relation to light pene- 
tration, 63. 
Seeds, as animal food, 167. 
Segregation of species, vertical in Lake 
Michigan, 82. 
Seines, illegal, 57. 
Selection of habitat: 
toleration in, 302-5. 
Sessile animals, food of: 97; in sea, 309; 
motile animals compared with, 300. 
Sewage, effect of: upon stream animals, 
17; upon oxygen content, 17; upon 
plankton, 17. 
Sheepshead, 85. 
Shiner: 79, 84; common, 115, 119, 120, 
140; golden, 65, 102, 115, 119, 120, 142, 
143, 156. 
Shore-bugs, 180. 
Shores, sandy: of large lakes, 78; of 
small lakes, 125, 126. 
Shrew: common, 189, 191, 196, 201, 262, 
269, 274; short-tailed, 201. 
Shrike, loggerhead, 275. 
Shrimps, scientific names: 
—Eubranchipus, 177, 178, 179, 278: 
serratus, 185, 279. 
—Palaemonetes paludosus, 126, 130, 135, 
152. 
Silversides, 85, 130, 135. 
Skunk, 12, 15, 169, 199, 262, 274. 
Slug caterpillar, 233. 
Slugs, scientific names: 
—Agriolimax campestris, 199, 200, 202, 
205, 236. 
—Pallifera dorsalis, 256. 
—Philomycus carolinensis, 206, 215, 240, 
241, 243, 247, 253, 254- 
Smeared dagger-moth, larva of, 190. 
Snails: aquatic, 90; in lakes, 130; reac- 
tions of, to light, 29; reactions of, to 
water current, 34. 
Snails, aquatic, scientific names: 
—Amnicola, 80, 148: 
cincinnatiensis, 117, 154. 
emarginata, 83. 
limosa, 83,99, 117, 121, 145, 146, 154. 
limosa parva, 154. 
limosa porata, 83. 
lustrica, 83. 
walkeri, 84. 
—Ancylus, 130: 
fuscus, 135. 
rivularts, 121. 
tardus, 121. 
—A plexa hypnorum, 192. 
300-305; law of 
