Ixviii 



THE PALEONTOLOGY OF MINNESOTA. 



CEhlertella, 364. 

 Oligocene, flora, 4. 

 Oolina salentina, 35. 

 Oolyte, flora, 2. 

 Operculiaa, 45, 28, 47. 

 arabica, 46. 

 complanata, 45, 4t>, 52. 



var. granulosa, 46, 52. 

 granulata, 46. 

 granulosa, 46, 47. 

 hardiei, 46. 

 irregularis, 46. 

 marginata, 46. 

 studeri, 46. 

 Operculum, 98, 105. 

 Operculum minimum, 45. 

 Orbiculzfilosa, 370. 

 lamellosa, 364. 

 squamiformis 356. 

 tnmcata, 364. 



Orhiculoidea, 363, 364, 365, 367. 

 lamellosa, 364, 366. 

 niorrisi, 363. 

 Orbitolites reticulata, 64. 

 Orbulina, 43, 28. 

 acerosa, 43. 

 continens, 43. 

 granulata, var. areolata, 43. 



var. atra, 43, 

 punctata, 43. 

 universa,'43, 52. 

 Oreodaphne, 5. 

 Orthidae, 417, 



Orthis,417, 335, 373, 377-378, 398, 409, 422, 423, 435, 

 441,449,451,454,455. 

 aequivalvis, 435. 

 amoena, 453. 

 basalis, 442. 

 bellarugosa, 434. 

 biforata, 455. 



var. crassa, 458. 

 var. lynx, 455 457. 



forma daytonensis, 455. 

 forma reversata, 455. 

 bisulcata, 470, 469. 

 borealis, 433*, 409, 467. 

 callactus, 421, 435. 

 calligramma, 418, 420, 435. 



var. davidsoni, 417, 418. 

 ctntrosta, 458. 

 charlottce, 424, 425. 

 circularis, 452. 

 conradi, 449, 448. 

 costalis, 419. 

 crassa, 458, 458. 

 cyclus, 445, 444. 

 davidsoni, 420. 

 deflecta, 422, 333, 421-424. 

 dentata, 468. 

 dichotoma, 436. 

 disparilis, 418, 430, 449. 

 electra, 439, 449. 

 elegantula, 442, 458. 

 emacerata, 445, 442, 444. 

 erratica, 469. 



flabellites, 432. 

 flabellulum, 431. 

 flssicosta, 436, 435. 

 germana, 301,312. 

 gibbosa, 451, 452. 

 hamburgensis, 44O, 441. 

 liuronensis, 405. 

 incurvata, 385. 

 insculpta, 435, 336*. 

 insignis, 381. 

 iphigenia, 431. 

 jamesi, 435. 

 jugosa, 446, 444. 

 kankakensis, 438, 436. 

 kassubi, 450. 

 lynx, 455, 454. 

 macrior, 445. 

 media, 450. 

 meedsi, 427, 421, 422, 430. 



var. germana, 428,334, 421, 471. 

 meeki, 445, 439, 444. 

 michelini, 418. 

 Minneapolis, 446, 448. 

 minnesotensis, 427. 

 multisecta, 444. 

 occidental is, 336*, 454. 



pectinella, 424, 420-425, 427, 428, 430, 431, 433, 

 437, 438, 439. 



var. semiovalis, 424. 



var. sweeneyi, 426, 421, 427, 428, 430, 467. 

 perveta, 450, 446, 448, 449, 452. 

 petrce, 431. 

 plana, 405, 

 platys, 424. 



plicatella, 436, 4 IS, 419, 421. 

 ponderosa, 407. 

 porcata, 432. 



proavita, 431, 421, 430, 432. 

 resupinata, 418. 

 retrorsa, 432. 

 rogata, 441. 

 sinuata, 432, 433, 435. 

 stonensis, 453. 

 striatida, 441. 



subsnquata, 446, 409, 418, 421, 448,450-454, 461. 

 var. circularis, 452, 448, 453. 

 var. conradi, 449, 333, 448, 450. 

 var. gibbosa, 451, 448, 450, 452. 

 var. perveta, 45O, 448. 

 subquadrata, 428, 418, 421, 423, 430-432, 435. 



437. 



swe&neyi, 426, 425. 



testudinaria, 441, 416, 418, 439, 442, 444-446, 

 451, 457. 



var. emacerata. 445. 

 var. meeki, 445, 442. 

 tricenaria, 418, 335*, 381, 417-420, 422, 441. 

 triplicatella, 435, 436. 

 whitefleldi, 437, 438. 

 Orthisidse, 377. 

 Orthisina, 377, 



diver sa, 378, 380. 

 verneuili, 378, 380. 

 Ortbisinae, 377. 

 Orthoceras, 77, 113, 317, 319, 320, 321. 



