538 



THE CHICAGO ACADEMY OF SCIENCES. 



Planorbis, 29. 84, 121. 

 albu - 



arcticus, 34. 

 " bicarinatus, 322, 388. 



bicarinatus royaleniis, 25 



binneyi, 20, 155. 



campanulas. 25. 



carinatus. 41. 



corneus, 41. 



marginatum. 41. 



panus, 247. 414. 



rotundatus, 54. 



spirorbis, 41. 



trivolvis, 20, 29. 



vortex. 41. 

 Planorbidae, 121, 124. 

 planulata. 285. 286, 289. 

 platystoma, 463. 

 plebeia, 300, 305, 313. 

 Pleurolimnaea, 3, 93, 103, 123, 124, 



198. 

 plica. 57 282 283, 285, 286,289. 

 plicata, 285. 



Polygyra albolabris, 340. 

 thyroides, 340. 

 Polyrhytis, 3, 103, 123, 124, 127, 458, 



460. 

 Pompholyx, 121. 122, 128. 

 praecellens, 465. 

 preblei, 445, 4-0-452. 

 proxima, 53, 337, J55-363, 367, 369. 



PSEUDOSUCCIXEA, 126, l62. 



pseudopinguis, 366, 395, 396. 



pugio, 353, 466. 



Pupa vermilionensis, 80. 



vetusta, 80. 

 Pupilla muscorum, 247. 

 pyramidata, 465. 

 Pyrgulifera, 84. 



Radix, 88, 122-125, 126, 162, 163, 178, 



179, 199, 421, 443. 452. 454, 457. 

 randolphi, 1, 179, 441, 443, 452-457. 

 raphidia, 149. 

 Recluzia, 463. 

 reflexa, 1, 2, 4, 6, 7, 9, 17, 20, 22. 46, 



50, 51. 94. 96, 109, 298, 312, 323-329. 



332-345, 347, 348, 351, 353-357, 359 



361-363, 465. 

 reflexis, 333. 



reticulata, 466. 



retusa, 467. 



Rissoa, 28. 



roseolabiata, 149. 314. 



rowellii, 303, 323 337, 349, j6>-364. 



rugosa, 463. 



rustica, 877, ^5S-270, 288. 



sanctaemariae, 21, 24-27, 149, 154, 156- 



160. 

 Sandria, 127. 

 scalaris (Walker*. 341. 

 scalaris (West.). 455. 

 scudderi, 100, 311. 

 Segmentina armigera, 21 

 senegalensis, 371. 

 septentrionalis, 301, 305. 

 sericata, 391. 

 serrata, 409, 410. 

 shumardi, 99, 101. 

 shurtleffi, 329, 330, 332. 

 sieverti, 101, 311. 

 similis, 91, 96, 101, 110. 

 Simpsonia, 126, 199, 200, 236, 296, 



297. 

 smithsoniana. 227-229, 234. 

 solida, 203, 382, 390, 391, 407. 444. 



447, 448, 449. 

 solidula, 371, 27 '- 



sonomaensis, 1, 213, 222, 223. 224. 225. 

 sordidus, 303, 305, 313. 

 spadicea, 463. 

 speciosa, 137. 

 Sphaerium, 21, 28. 



occidentale, 19, 233. 

 Spirogyra, 20, 21. 

 Stagnalis, 1. 2. 4. 6. 7-9, 13, 15, 17, 



27, 28. 32, 33. 39. 41, 42, 44, 46. 48. 



52, 34, 63, 67, 84, 102, 7J6-157, 161, 



162, 166. 168, 180, 191, 200, 3:7 584 



431, 436. 

 Stagnicola, 94, 96, 105, 110, 124, 126, 



127, 163, 179, 199, 234. 235, 296, 



297, 298, 307, 347, 369. 373, - 



- : :. 458, 461. 

 STEARXSI, 53, 84, 102, 146. 

 sterkii, 20, 241, 2^-250, 23S. 267. 

 Stohdoma, 89. 

 strigata, 382. 

 strigosa, 171-174, 382. 



