CORRELATION OF STRATA. 
Hudson or 
Trenton Period. nein 
Stones Black Trenton 
Groupe ele Guecam je croun: 
LAMELLIBRANCHIATA. alee ays) F ; 
al®lslg} as] s a 8 
2 | 21a eel iadlesie te) | os 
& 3 a Sie Kis 2 }as/ Sia & BR 
S)SISIE/S laste l@s| esl a 3 3 
MO;)es)/et18]alsslolsal aefo 3 o 
Hlo]/S}S)ol"Sis leo of] al 8 g n 
Jo] ] 213/13 lool gs sas] B] &] 8 5 2 
ofeF)/s/Sis)] eS lesl s las] 2a] 8 = q 
el /3/2|8 (Sige )el2sisls(s] 2 | & 
BID |e \nl|e|o ealo eals|p/e S) = 
Vanuxemia abrupta, n. sp............... 560 x 
Wanuxemliam Obayelalile src eeeecmereett 560 ii + 
Vanuxemia wortheni, n.sp..... ...... .| 561 Pl @ 
Vanuxemia decipiens, n. sp.............. 562} x | ? 
Matheria rugosa Ulvich.................. 563 x 
Whitella obliquata Ulrich............... 565 
Whitella quadrangularis Whitfield....... 566 
Whitella sterlingensis M. & W 
Whitella compressa Ulrich.......... 3K || ox 
Whitella concentrica Ulrich x8 |] ox 
Whitella rugatina, n. sp............4.... Sx |fiex: 
Whitella megambona Whitfield.......... 570) x 
Whitella scofieldi Ulrich......... ....... 571 x 
Whitella truncata Ulrich:............... 572 
Whitella subcarinata, n.sp.............. 572 
Whitella ventricosa Hall................. 573 
Whitella pracipta Ulrich................] 574 
Plethocardia umbonata Ulrich........... 576 x 
Plethocardia suberecta Ulrich...........] 577 
Ctenodonta nasuta Hall.................. 584 XEN) x 
Ctenodonta nasuta var.robusta, n var...| 585 i ? 
Ctenodonta subnasuta, n. sp............. 585) 
Ctenodonta oviformis, n. sp.............. 586 
Ctenodonta cuneiformis, n. sp...........| 587 xX | 
Ctenodonta gibberula, Salter............ 587 x + 
Ctenodonta carinata, n.sp............... 589 
Ctenodonta planodorsata Ulrich......... 589 x 
Ctenodonta longa, n. sp................-. 590 x 
Ctenodonta logani Salter...........- .... 591 + 
Ctenodonta nitida Ulrich....... ....... 592) 3 || 52 
Ctenodonta medialis, n. sp.............-. 593 3K 
Ctenodonta scofieldi, n. sp.............. 593 x 
Ctenodonta socialis, n. sp................ 594 x 
Ctenodonta fecunda Hall........ ....... 595 
Ctenodonta calvini, n. sp................. 596 
Ctenodonta albertina, n. sp.......... ‘oon | Bilal 
Ctenodonta filistriata, n. sp.............. 599 
Ctenodonta simulatrix, n. sp............. 600 
Ctenodonta compressa Ulrich............ 600 ? x 
Ctenodonta astartiformis Salter......... 601 x 
Ctenodonta intermedia Ulrich........... 601 
Ctenodonta alta Hall.................... 602 
Ctenodonta recurva Ulrich............... 605 
Ctenodonta similis Ulrich................ 604 
Ctenodonta obliqua Hall..... ate mean Goa 604 
Ctenodonta hamburgensis Walcott...... 605 x 
Clidophorus consuetus Ulrich........... | 606 
Clidophorus neglectus Hall.............. 607 
Lyrodesma acuminatum, n. sp........... 609 5K 
Lyrvodesma cannonense, n. sp............. 610 
-Lyrodesma major Ulrich................. 611 
Technophorus subacutus Ulrich......... 614] ? x 
Technophorus extenuatus Ulrich........ 614 x |] 5z 
Technophorus filistriatus Ulrich..... .. 615 x 
Technophorus divaricatus Ulrich........ 616 oe 
Allodesma subellipticum Ulrich......... 617 
Rhytimya sinuata, n. sp................. 
Cuneamya truncatula, n. sp.............. 
Cuneamya oblonga, n. sp................. 
Sphenolium parallelum, n. sp T Nar 
Sphenolium striatum, n.sp.............. 
Saffordia ventralis, n. sp............. ... 
Saffordia sulcodorsata Ulrich 
Saffordia modesta Ulrich................ 
New York. 
Cxvil 
Canada. 
