CORRELATION OF STRATA. CXX1 
Hudson or! 
Trenton Period. ase 
Stones Black Trenton 
i River 
Genes Gon Group. 
CEPHALOPODA 
é : 23 a : rl 
ick _\/Ez/2] 12 c3e| [2] 3 
OSTRACODA. a = 8 = s 2 ie 3 5 Fa 2 
a es my co [3 4 5 
alei|Ele eles slesielsle| = | & | Z 
a 3) =) fo) ele |Ao] a0 ° =| n © GI 
OE) 8) Se Ss SS) Ba el) eae 2 g me e 
o BPlSele] a] gs |ss]s la sic feol|s ° a Ee q 
eo. § Ss/2/8/ 2/52/53 /2sle]/5]8 a © D x 
alt |>l/n]e|o alo ezla}o}e 5 SI a S) 
CEPHALOPODA. 
Nanno aulema, n. Sp......------.++-+++++ 770 x |? 
Cyrtocerina (?) schoolcrafti, n. sp........ 7714 x 
Cameroceras proteiforme Hall........... T17) x| x cK SBTUL] § iy B 
Cameroceras hennepini, n. Sp...........- 779) _ 
WAMMEKOCELASH SDseweleb terete eter tetas otietereiereterclc 7801 x | x 
Cameroceras, Sp. DOV...........2++. eens 780] x | x 
Actinoceras bigsbyi Stokes............. 781 x x alx SB SBT mT 
Actinoceras beloitense Whitfield......... 782 ot + 
Actinoceras remotiseptum Hall.......... 782) x | ? ae 
Orthoceras nicolleti, n. sp............... 784] x | 2 
Orthoceras anellus Conrad............... 784 x B ap B 
Orthoceras perroti, 0. Sp..........--..-.- 785 x! ?R 
Orthoceras lesueuri, 0.Sp..............-- 785 x SB 
Orthoceras bilineatum Hall.............. 786 x x B T T B 
Orthoceras olorus Hall................... 788 x x Ss T 
Orthoceras tenuistriatum Hall.......... 788] x | ? 
Orthoceras sociale Hall.................. 789 x xe |] oe|) 10) 215) 
Orthoceras beltrami, n. sp............... 789 x 
Orthoceras multicameratum Hmmons. ..| 789 X¢ || 5x || 3X x s s 
Orthoceras junceum Hall................ 790 x x|/?]x SBT a 7 
Orthoceras cf. amplicameratum Hall.....} 790 x uy Te B 
Triptoceras planoconvexum Hall........ 791 x px SB 
Triptoceras planodorsatum Whitfield. .| 792 x 
Triptoceras Owenl, D. Sp..............-.-- 792 x B 
Ute DIOCEMAS N05 (2)acosd o0d0ce sponge eoaood | yick} x 
Triptoceras lambi Whiteaves............ 793 x 
Gonioceras anceps Hall.................. 794 x Ss B B 
Gonioceras occidentale Hall.............. 795 Ta s 
Poterioceras apertum Whiteaves......... 796 x Ty 
Clinoceras mumizeforme Whitfield....... 797 x ? s 
Oncoceras exiguum Billings............. 798 ?Ilx iT 
Oncoceras minnesotense, 1. Sp........... 798 x 
Ontvocerasycustelalllgecss cc setiree esc: 799 x 
Oncoceras cCarveri, 0. Sp.............--0+- 801 x 
Oncoceras douglassi, n. Sp............... 801 x 
Oncoceras pandion Hall.................. 802 x 
Cyrtoceras neleus Hall............-...... 804 x 
Cyrtoceras bondi (?) Safford............. x SB Ss 
Cyrtoceras hallianum d’Orbigny.......... 805 xe |] 3z Tr vr 
Cyrtoceras billingsi Salter............... 806 x Ss B 
Cyrtoceras houghtoni, n. sp.............. 807 x 
Cyrtoceras featherstonhaughi, n. sp...... 807] Px 
Cyrtoceras minneapolis, n. sp............ 808 x 
Cyrtoceras corniculum Hall.............. 809 pe 
Cyrtoceras norwoodi, n.sp...............] 809 af 
Cyrtoceras shumardi, n. sp............... 810 x 
Cyrtoceras scofieldi, n. sp................ 810 if 
Gyroceras duplicostatum Whitfield. .....] 811 t 
Hurostomites undatus var. occidentalis ; 
le ul Saas m mona opaeemaro ae Bean teide 811 x B 
OSTRACODA. 
Leperditia fabulites Conrad.............. 634) x | x} + s Ss s B?T 
Leperditella canalis, n.sp...............- 637] x | x | 
Leperditella persimilis, n. sp............. 637 se 
Leperditella macra, n. sp................ 638) x 
Leperditella germana Ulrich............. 638 Wl We 
Leperditella (?) dorsicornis Ulrich........ 639 tT 
Schmidtella crassimarginata Ulrich...... 640 P|) ir s ~ 
Schmidtella affinis, n. sp................- 641 x/n 
Schmidtella umbonata, n. sp............. 641 x 
Schmidtella incompta, n. sp............. 642 xe 
Schmidtella incompta var. subsequalis, 
Wb Wats osdeodanboocgbesbooOUDDUUOBIOOOL.OG 642 n 
Schmidtella brevis, n. sp...............5- 642 x 
