INDEX. 
Adams county, geology of.• • 43 
Adams county, Quaternary system in. 44 
Adams county, Coal Measures in. 48 
Adams county, St. Louis limestone in .. 51 
Adams county, Keokuk limestone in. 53 
Adams county, Burlington limestone in.. 55 
Adams county, Kinderhook group in.57 
Adams county, economical geology of.... 58 
Adams county, soil and timber in. 60 
i35 /- ''X'lethopteris.391 
Alethopteris crenulata.392 
Alethopteris cristata.395 
Alethopteris erosa. 394 
Alethopteris emarginata.398 
Alethopteris falcata.396 
Alethopteris Hallii.394 
Alethopteris Hymenophylloidcs.393 
Alethopteris longifolia.469 
Alethopteris lanceolata.398 
Alethopteris Mazoniana.391 
Alethopteris muricata...395 
Alethopteris Pluckneti.395 
Alethopteris Pennsylvaniaca.469 
Alethopteris solida.397 
Alethopteris spinulosa.396 
Amblipterus macropterus.348 
Annularia inflata.423 
^ ^ _ Annularia longifolia.422 
Antliodus sarcululus.356 
., , „. Aphlebia.410 and 414 
^)CO ^^terocarpus grandis.469 
Asteroptychius triangularis...370 
Asterophyllites grandis.424 
Asterophyllites foliosus.424 
Asterophyllites rigidus.424 
Asterophyllites tuberculatus.424 
Brown county, geology of. 62 
Brown county, Quaternary system in.63 
PAGE. 
Brown county, Coal Measures in. 65 
Brown county, St. Louis limestone in.... 68 
Brown county, Keokuk group in. 69 
Brown county, economical geology of.... 70 • / 3<S 9. 
Brown county, soil and agriculture.73 f-, ■ 
t/r -i i • Lfl i , K.// ibi) a) yy /. , . r / O 
Callipteris Sullivantii.. .468 Ca\cboLcv^^ . />• ■ 
Carpolithes bullatus.463 
Carpolithes corticosus.462 
Carpolithes persicaria .462 
Cass and Menard counties, geology of... 163 
Cass and Menard counties, Coal Measures 
in.165 
Cass and Menard counties, economical ge¬ 
ology of.173 
Calhoun county, geology of.. 1 
Calhoun county, St. Peters sandstone in.. 3 
Calhoun county, Trenton group in. 4 
Calhoun county, Cincinnati group in...... 5 
Calhoun county, Niagara limestone in.... 6 
Calhoun county, Hamilton group in. 8 
Calhoun county, Kinderhook group in.... 9 
Calhoun county, Burlington limestone in. 12 
Calhoun county, Keokuk limestone in... . 14 
Calhoun county, St. Louis limestone in... 15 
Calhoun county, Coal Measures in. 15 
Calhoun county, Quaternary system in.... 17 
Calhoun county, economical geology of... 18 
Calhoun county, soil and agriculture of.. 22 
Cap au Gres, fault. 2 
Caulopteris acantophora.458 
Caulopteris intermedia.459 
Caulopteris obtecta.457 
Champaign and Ford counties, geology of..272 
Chondrites Colletti.379 
Coal, analyses of. .33, 50, 58, 85, 86, 104, 
105, 257, 259, 316 
Coal shaft, Jacksonville.159 
Coal shaft, Bloomington.186 
