exlviii THE PALEONTOLOGY OF MINNESOTA. 
Ortonella, 535, 486. 
Ostracoda, chapter on, 629-693. 
Owenella, $47, 845, 848-850, 856, 857, 868, 876. 
antiquata, 1080*, 848. 
Oxydiscus, 912, 850, 851, $52, 858-860, 868, 913, 914, 
926. 
acutus, 869*, 852. 
cristatus, 914, 852, 913. 
curvilineatus, 852. 
delanonii, 652. 
disculus, 913. 
discus, 852. 
imitator, 852. 
magnus, 852. 
orbiculatus, 852. 
planissimus, 852. 
scutigera, 852. 
subacutus, 913, 852, 914. 
Pachydictya foliata, 685. 
Pachydomella, 632. 
Palewacmea, 836, $21, 825, 837, 838. 
humilis, $37, 836. 
irvingi, 836. 
orphyne, 836. 
quebecensis, 836. 
solarium, 836. 
typica, 822, 836. 
Paleanatina, 487. 
Palzanatinide, 487. 
Palearca, 584-536, 539, 
ventricosa, 573, 540, 574. 
Paleocardia, 489, 485. 
Paleeoconcha, 578, 580, 600, 605. 
faberi, 604, 605. 
obliqua, 604. 
Palzocypris, 630. 
Paleoneilo, 582, 486. 
Paleopinna, 485. 
Palzosolen, 487. 
Pallial line, 480, 476. 
Palpebral lobe, 697. 
Paracardium, 486. 
Pararca, 486. 
Pararcide, 486. 
Paracyclas, 487. 
Patella, 819. 
Patellacea, 819, 818, 844-846. 
Patellide, $19, 816, 820, 821, 823, 825, 837, 842. 
Patellostium, $54, 915. 
Pecten, 479. 
Pectenidz, 485. 
Pectinibranchiata, 930, $19, 844. 
Pelecypoda,: 475, 484, 489. 
Penenka, 486. 
Peristome of Gastropoda, 815. 
Permian Ostracoda, 631. 
Pernopecten, 485. 
Perotrochus, 949, 960, 
Phacopid, 732, 726. 
observations on American Lower Silurian, 732. 
Phacops, 704, 734, 751, 752. 
callicephalus, 731. 
lopatini, 729. 
orestes, 734, 
rana, 704, 705, 
trisulcatus, 734. 
Phanerotinus, 1024. 
eboracensis, 1024. 
laxus, 1024. 
paradoxus, 1024. 
Phanerotrema, 952, 949, 990, 991, 1008. 
labrosa, 952. 
Philomedes, 6382, 631. 
philoxene, 1024. 
Pholadella, 619, 487, 517, 620. 
Pholadellidee, 618, 487, 526, 623. 
Phorus, 1024. 
Phragmolites, 851, 904, 905. 
compressus, 905. 
Phragmostoma, 926, 854, 857. 
cunule, 927. 
cymbula, 927. 
natator, 927. 
Phreatura, 632. 
Phthonia, 486. 
Physa, 815. 
Physetomya, 487. 
Piloceras, 767, 765, 768, 769, 772, 774, 776, 777. 
amplum, 768, 769. 
canadense, 769. 
explanator, 768, 769. 
gracile, 769. 
invaginatum, 769. 
newton-winchelli, 767, 768*, 769, 812. 
triton, 769. 
wortheni, 769. 
Pinna, 485. 
Pinnide, 485. 
Pithodea, 960. 
Placentula, 632, 681, 683. 
excavata, 682. 
inornata, 656. 
Placophora, 817. 
Platyceras, 1068, 1044, 1064, 1069. 
depressum, 1069. 
wisconsinensis, 1068, 1069. 
Platyceridsx, 1044. 
Platyloron, 960. 
Platymetopus, 746, 748, 752, 753. 
bicornis, 748*, 753. 
cucullus, 746*, 747, 753. 
jukesi, 753. 
minganensis, 753. 
robbinsi, 747*, 748, 753. 
trentonensis, 753. 
Platynotus, 753. 
boltoni, 753. 
breviceps, 753. 
harrisi, 753. 
nereus, 753. 
trentonensis, 752. 
Platyostoma, 822. ~ 
trigonostoma, 940. 
Platystoma, 1064. 
Plectambonites sericea, 746, 798. 
Plethocardia, 575, 487, 576. 
1 oan 
