538 THE CHICAGO ACADEMY OF SCIENCES. 
Planorbis, 29, 84, 121. 
if albus, 54. 
: arcticus, 54. 
ee bicarinatus, 322, 388. 
re bicarinatus royalensis, 25. 
e binneyi, 20, 155. 
= campanulatus, 25. 
carinatus, 41. 
corneus, 41. 
marginatus, 41. 
parvus, 247, 414. 
rotundatus, 54. 
spirorbis, 41. 
trivolvis, 20, 29. 
vortex, 41. 
Planorbide, r2r, 124. 
planulata, 285, 286, 289. 
platystoma, 463. 
plebeia, 300, 305, 313. 
Pleurolimnza, 3, 93, 103, 123, 124, 
198. : 
plica, 87, 282, 283, 285, 286, 289. 
plicata, 285. 
Polygyra albolabris, 340. 
thyroides, 340. 
Polyrhytis, 3, 103, 123, 124, 127, 458, 
460. 
Pompholyx, 121, 122, 128. 
precellens, 465. 
preblei, 445, 450-452. 
proxima, 53, 337, 358-363, 367, 369. 
PSEUDOSUCCINEA, 126, 162. 
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, 362-364. 
rugosa, 463. 
rustica, 877, 268-270, 288. 
sanctemariz, 21, 24-27, 149, 154, 156- 
160. 
Sandria, 127. 
scalaris (Walker), 341. 
scalaris (West.), 455. 
scudderi, zoo, 311. 
Segmentina armigera, 20. 
senegalensis, 371. 
septentrionalis, 301, 305. 
sericata, 391. 
serrata, 409, 410. 
shumardi, 99; 101. 
shurtlefh, 329, 330, 332. 
sieverti, roz, 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. 
solidulay 371. 375: 
sonomensis, 1, 213, 222, 223, 224, 225. 
sordidus, 303, 305, 313. 
spadicea, 463. 
speciosa, 137. 
Spherium, 21, 28. 
cf occidentale, 19, 233. 
Spirogyra, 20, 21. 
Stagnalis; 1,02) 4 "657-0. staan 
27, 28, 32, 33, 39, 41, 42, 44, 46, 48, 
52, 54, 63, 67, 84, 102, 136-157, 161, 
162, 166, 168, 180, 191, 200, 357, 384, 
431, 436. 
Stagnicola, 94, 96, 105, 110, 124, 126, 
127, 163, 179, 199, 234, 235, 296, 
297, 298, 307, 347, 369, 373, 403, 
452, 458, 461. 
STEARNSI, 53, 84, 102, 146. 
sterkii, 20, 241, 248-250, 258, 267. 
Stolidoma, 89. 
strigata, 382. 
strigosa, 171-174, 382. 
