PLATE IV F— Continued. 



Okbiculoidea Xewbekryi, II;ill. 



Fig-. IS. The same featui'es; showing- the strnnu- elevation of the jivp» h.u <i,» ^ ^ e „ ■■ 



;:^;£i^^^=:,"^^^"^ ^'-"ea.^hot.,hX.(;i.:^^->:^ii::'\.!^^/:^^^'^:,:fjtr:^ z 



Wavei-ly group. Cuyahoga Fallx, Ohio. 

 (From the original locality, a ferruginous ban,l about UO feet below the .conglomerate.) 



CEHbp:RTELLA s.-gen ^•o^^ 



Page 120. 

 U1.HLERTELLA PLEURITES, Mcck. 



"■ 1.".™, atat" ''x s' '°""'' """''°°°- '" ""'* "* """ '" *• •"* ■" ■"«»"> *"'l "■• •Pl«.l 



Waverly group. Newark, Ohio. 



ORBICULOIDEA, D'Orbignv. 



Page 1-20. 



Okbiculoidea Loden.si.s, Vanu.xein. 



Fig. 21. The int^.-nal characters of the pedide-area; indicating the unu.sual brea.Uh au,i depth of the base 

 ^^'yS'-f'-'^^'^'-^'^fiow^^^.r^Uvalh; al,.o the iuter.'uption in the ornamentfon of the shdl 

 me ap'tur-r X 4 ""'"' ^"'""'"^' ''"''"'""^ ""' '""^ "'' "'""" "*' *"« p.-imUWe margins of 

 Genesee shale. Lodi, iV. 1'. 



Okbiculoidea, .sp. iiidct. 



Fig. 22. A natural cast of the interior apical portion of the brachial valve ; showin- the -interior and no^ 

 tenor muscular ridges. X3 .-■"- wino lue .luieiioi ami pos- 



Chemung group. Warren. Pa. '• >' 



Okbiculoidea nitida, Pliillips. 



Fig. 23. The pe,iicle-area of an extremely youug shell, having a diameter of 1 mm. The fc-ameir is a 



marginal sht extending, with divergent edges, for almost the entire radius of the valv^ Ki 



v:» OA . ">^■•V"^^• '^'; l'^''>i'^le-gr.ove appears in an incipient stage. X SO. =' « tne Nalxe. At 



F.g. 2:,. A later stage of growth, exhibited by a .specimen 7 mm. in diameter. Here the andes m-i.le bv 



Tj- o„ ,„, . , i^oweiuoai Measures Spruiujitld. IlUvois. 



Ftg. 2fa. I he internal pedicle-.urea of a small but mature individual; showing the base and lateral walls 



P- 0- -PP."' '^' *f'-»o^-ef 1^' <he slight callosity at the apical extremity. X 7 



Fig. 2,. The externa surface of a similar specimen ; showing the general form of the groove at matnritv 



Fig. 28. The entire valve of which tig. 27 represents the pedicle-area. X 2 

 . Coal Measures. G-rovei; Mi.^.wuri. 



Okbiculoidea, sp.. Meek. 



at iNont: £i '•'■'i'E 1>^1 r; ''"'^T^---' '■•"■•■';-■. with a .-.mall, umnd or ova'l for" 



