144 
INDEX. 
Page. 
Leiopteria rafinesquii 96 
Leiorhynchus fauna, geologic place of -46 
Leiorhynchus globuliforme, occurrence of. 96, 98 
Leiorhynchus globuliforme stage or faun- 
ule, geologic place of 47, 97-98, 115 
Leiorhynchus laura, occurrence of 62, 63 
Leiorhynchus mesicostale, occurrence of . . 72, 
74,76,77,95,98 
Leptodesma matheri, occurrence of 91 
Lepdodesma sociale, occurrence of 96 
Limestone, uniform character of fossils of, 
through long periods 33 
Limnobios, definition of 14 
Lingula, occurrence of 90 
Lingula fauna, geologic place of 45, 46 
Lingula complanata stage or faunule, geo- 
logic place of 47 
Lingula spatulata stage or faunule, geo- 
logic place of 47, 48, 69 
Liopteria. See Leiopteria. 
Lithologic characters, valuelessness of, in 
discriminating time equivalency of 
formations 101 
Livonia salt shaft, faunas of 63-64 
Loxonema delphicola, occurrence of 90, 95 
Loxonema hamiltonise, occurrence of 95 
Lunulicardium fragile, occurrence of 95 
Lunulicardium ornatus, occurrence of 77 
Lyriopecten priamus, occurrence of 96 
Lyriopecten tricostatus, occurrence of 96 
M. 
Macrodon hamiltonise, occurrence of 90 
Mackenzie River Valley, faunas of, rela- 
tions of 79 
Marcellus shale, geologic place of 50,122 
thickness of 93 
Maryland Geological Survey, paleontologic 
work by 8 
Mauch Chunk formation, stratigraphic 
equivalents of 122 
Metropolis of a fauna, definition of term. . . 25 
Michigan, Hamilton formation in, fauna of. 65 
Migrations of faunas, geological expres- 
sion of 33-41 
observations on 18, 23-24, 31, 34-41, 97-116 
variations of specific forms due to 40-41 
Mingling of faunas, expression and ex- 
amples of 31, 103 
Modiella pygmsea, occurrence of 56 
Modiomorpha complanata, occurrence of. . 70 
Modiomorpha cf. concentrica, occurrence 
of 91 
Modiomorpha mytiloides, occurrence of. . . 90 
Mndinniorpha quadrula, occurrence of 96 
Modiomorpha subalata var. chemungensis, 
occurrence of 72, 74, 77 
Monobion, definition of term ' 102 
Monroe and Teller, cited on Hamilton 
fauna of Wisconsin 65 
Moscow shales, geologic place of 50 
Mutation of species, definition and discus- 
sion of 17, 81-82 
Myrtilarca carinata, occurrence of 96 
Mytilarca chemungensis, occurrence of . 85,86,87 
N". 
-face. 
Necton, definition of 14 
Nucula bellistriata, occurrence of 51, 
56, 58, 59, 60, 62, 63, 75 
Nucula corbuliformis, occurrence of 51, 
56, 58, 59, 60, 62, 63, 65, 71, 75 
Nuculites cuneiformis, occurrence of 95 
Nuculites oblongatus, occurrence of 51, 
56, 59, 60, 62, 63, 71, 75, 95 
Nuculites triqueter, occurrence of 51, 
56, 58, 59, 60, 62, 63, 64, 75 
O. 
Ohio, Devonian formations of, correlation 
of 120-123 
Ohio shale, correlation of 109, 112 
Old Red sandstone, intermediate faunas of. 7 
Olean conglomerate fauna, geologic place 
of 47 
Oneonta sandstones, character and fossil 
content of 110-111 
correlation of. . 99, 100, 103, 104, 109, 112, 120, 122 
deposition of, conditions during Ill 
fauna above 94-95, 97 
fauna of 48, 97 
faunal shifting in 97-103,115 
geologic horizon of, variation of, in dif- 
ferent localities 108-109 
shifting of faunas coincident with de- 
position of 97-103, 115 
stratigraphic horizon and equivalents 
of 99, 100-103, 104, 109, 112 
thickness of 93 
Ontario, Canada, Hamilton formation in, 
fauna of 64-65 
Onychodus hopkinsi, occurrence of 96 
Orbiculoidea media, occurrence of 64, 77 
Orbiculoidea neglecta, occurrence of 77 
Organic values, measurement of, discussion 
of methods of 124-134 
Orthis (=Schizophoria) , common features of 
many species of 85 
Orthis carinata, occurrence of 86 
Orthis (Dalmanella) leonensis, occurrence 
of.: 87 
Orthis leonensis zone, geologic place of 46 
Orthis (Schizophoria) impressa, occurrence 
of 85,86,87,95 
Orthis (Schizophoria) tioga, occurrence of. 83,86 
Orthis tioga stage or faunule, geologic place 
of 45,48 
Orthis (Schizophoria) tulliensis, occurrence 
of 78 
Orthis vanuxemi, occurrence of 64 
Orthoceras bebryx cayuga, occurrence of. . 74 
Orthoceras nuntium, occurrence of 64 
Orthonota undulata, occurrence of 95 
Orthothetes arctistriatus, occurrence of. 57, 58, 64 
Orthothetes chemungensis, occurrence of. . 79, 
83,85,86,87,92 
Orthothetes chemungensis arctistriatus, oc- 
currence of 92 
Owego, N. Y., fossils found at 89-90 
Palseanatina typa fauna, formation con- 
taining 46, 48 
