CORRELATION OF STRATA. . Cxi 
ee LEE EEE 
Hudson or 
Trenton Period. [Paes 
Stones Black TMirentor 
River River 
PORIFERA, Group. | Group. | @TOUD- 
C@HLENTERATA, scllbas ols) a ; 5 
s/S]e)o}] S}4] 3]. a} 6s 
AND eqeed| a (2 | cle ieee aipeaeas 
slslalflelssslssio]s/—) = ; ; 
BRYOZOA. SlSlElSl/elSclolsalalel/e] «= 3 a 
»/2/Slelsisyelssie|a)s] s 2 5 
8/%|2|S| 3 Se] 8 esl 5 g > 
-1{2/5/o)]3] elses] 8 lesa] a] 48 et a 
&1°)2/3(2/8 2215 Be slels| 2 Beales 
siels|Flelsealoleels/5/e] 3s = Zz 
Receptaculites oweni Hall............... 57 x¢ |] Xe] 3 
Receptaculites sp. undet......-.--.-.-.-- x 
Ischadites iowensis Owen..............-- 64 2p |liexalline 
FRA HELeL etl LO Sas Wl] Chis ele etcieierleletetaieletelal= 15 x |] 3 |] 28 
Rauffella palmipes Ulrich................ 76 x 
Heterospongia subramosa Ulr........... 79 se || 1b ie 
Hindia inzequalis Ulrich. ..............-. x|T 
TeinG bes RNA) MMA. saboogssossoaDebaece 79) x] x 7, av 
Cylindroccelia minnesotensis Ulr......... 78 2 || oe |] 
Brachiospongia (?) robbinsi Ulrich....... x 
Calathium (?) clavatum Ulrich.......... x 
Calathium (?) hexagonalis Ulrich........ x 
Camarocladia dichotoma U..& H......... 6 (11 
Camarocladia fruticosa Ulrich........... x 
Camarocladia rugosa Ulrich............. f B 
Solenopora compacta Billings............ 80 x SBTR mT B 
Diplograptus pristis ? Hall............... 81 axe 2U UH UH 
Diplograptus putillus Hall............... 82 x U 
Climacograptus typicalis Hall........... 82 +x TU H 
Lichenaria typa, 0. Sp.............+. +. 83 x x 
Lichenaria minor, D. Sp.........-......-- 84 2s 
Columnaria halli Nicholson.............. 85 x] x SBR SB B 
Streptelasma profundum Conrad........ sg] X | X | x] X} x} x SB SB SB 
Streptelasma parasiticum, n. sp......... 89} x x 
Streptelasma breve, n. Sp..........-+-4-- 92) x 
Streptelasma corniculum Hall........... 90 x| x ae 
Streptelasma rusticum Billings.......... 93 x R 
Protarea vetusta Hall...................- 94 BS ; m 
Protarea vetUsta VaL.........-2.2--+0 +005 x R 
RETA CUMS MNIMUS VATs aeselclc -sieteicle «re a\eleie10 x R 
Aulopora (?) trentonensis, 0. sp......-..- 95 P| x 
BRYOZOA. 
Vinella repens Ulrich................-.+- 114 2s 
Stomatopora proutana Miller............ 117 x} x x/xXj|/n TP) fe Wy aoe a? 
Stomatopora inflata Hall........- ...... 117 x L T 
Stomatopora turgida Ulrich.............. 118 T 
Proboscina tumulosa, n. sp.........-..-- 119 x 
Berenicea minnesotensis Ulrich.......... 120 3S || 28 5 
Diastoporina flabellata Ulrich........... 122 ‘| 
Mitoclema (?) mundulum'Ulrich......... 123 n 
Rhinidictya mutabilis Ulrich............ 125 x, X| x) X|]*X/n ae ST 
Rhinidictya mutabilis var. major Ulr....} 127 x |x| x 
Rhinidictya mutabilis var. senilis, n. var.} 127 x 
Rhinidictya paupera Ulrich.............. 129 x 
Rhinidictya neglecta, n. Sp............-. 130 2 T 
Rhinidictya exigua Ulrich............... 131 x} x xs 
Rhinidictya minima Ulrich.............. 132 n 
Rhinidictya minima var. modesta, n. var.} 133 n 
Rhinidictya fidelis Ulrich................ 134 x . 
Rhinidictya trentonensis Ulrich......... 135 x| x s 
Rhinidictya nicholsoni Ulrich........... x Ss Ss 
Rhinidictya grandis, n. sp............... 136 fie a s 
Rhinidictya pediculata, n. sp............ 1STEX 5 Ss 
Eurydictya“multipora (? Hall sp.)........ 139 2 x oy T 
Phyllodictya frondosa Ulrich............ 142) || 28 SB 
Phyllodictya varia, n. 5p...........-++-- 144 x 
Pachydictya foliata Ulrich.............. 149 x b s Ss 
Pachydictya occidentalis Ulrich......... 151 a - 
Pachydictya fimbriata Ulrich............ 152 x| xX]: Ss 
Pachydictya elegans, 0. Sp...........---- 154 5 x 
Pachydictya acuta Hall......... Pac rnisis 155 3 x|x T T T 
Pachydictya pumila Ulrich.............. 157 : n T 
Pachydictya magnipora Ulrich.......... = 
Doe EEE 
Oanada. 
HHH 
