PLATK l.XIl— Conlliiuoil. 



Gbnus CAMAROPHORIA, Kino. 



l>age in. 

 CaMAKOPHOIUA KHOMBOIDALIS, sp. IIOV. 



Wig. >B. Dorsal view of a specimen of somewhat btUow the average size. 



Vig. 86. Frontal view of a similar sjHH-imen enlarffed ; showing' the character of the marginal plication 

 and the development of fold and sini». X 2. 



ngs 87, 88. 89. Dorsal, vential and front views of an average aiiult shell, possessing a shanier median fold 

 and sinus, stronger plication, and showing the median septum in each valve through the sub- 

 stance of the shell.,' 



Comiferous limestone. Peru, Indiana. 



Subgenus PUGNAX, s.-gen. nov. 



I'age 20-2. 



PuGNAX (?) Dawsonianus, Davidisoii. 



Fig. 30. Donwl view of a young shell without plication. X 2. 



Rgs. 31, 32, 33. Dorsal, profile and front views of a .shell with mature characters ; showing the marginal 

 plication and the elevation of the beak. X 2. 



Carboniferoiw limestone. Windsor, Nova Scotia. 



Genus CAMAROPHORIA, King. 



Page 21S. 

 CAMAROPHORrA SUBCUNEATA, Hilll. 



Fig. 34. Dorsal \-iew of a young, but freely plicated shell ; showing the shallow valves, subtriangular out- 

 line, and long cardinal slopes. 



Figs 3f), 36. Protile and fi-ont views of a mature and gibbous shell, showing the character of the plication 

 and the broad, concave canlinal slopes. 



Kg. 37. A portion of the interior of the pedicle-valve, showing the spondylium sui)poi-ted by a median 

 septum. The summits of the teeth have been broken, showing their lateral union with the 

 walls of the shell. X 2. 



St. Louis group. Waxtmigton cdunty, Indiana. 



CAMAKorHouiA suBTKiGoNA, Mock .iikI Woitlieii. 



Pig*. 88, 39, 40. Cardinal, frontal and ventral views of an internal cast; showing the contour of the shell, 

 the denticulate margin of the valves on the broad cardinal slopes, the sharjily serrate anteiior 

 and lateral margins and the (ravity left by the spondylium and median septum of the 

 pedicle-valve. 



Chert of the Burlington limestone. Burlingtiin, lovxi. 

 Figs. 41, 43. Internal casts of pedicle-valve.s showing the form of the muscular impression. 



Keokuk group. Nauvoi), lllinm^. 

 Fig. 43. The umbonal jwrtion of an internal ca.st of both valve.s, enlarged, the pedicle-\alve being above. 

 This figure shows the cavity of the spondylium, median septum and oblique dental plates of 

 the pedicle-valve ; median septum and small umbonal spondylium of the brachial valve. X 3. 

 Chert of the Burlington limestone. Pike county, Missouri. 



Subgenus PUGNAX, 8.-gkn. nov. 



•Page 2(W. 



PuoNAX Missouri ENsrs, Swallow. 



Figs. 44. 45. Cardinal and profile views of an internal cast of a large specimen ; showing the contour of the 

 shell, the cavities of the median septunj of the bratthial valve, the dental platOK ami the fore- 

 »hortene<l outline of the mus<-ular ai-ea in the ))edicle-valve. 



Yellow standstones of the Burlington group. BurlingUm, Iowa. 



