PLATE EXII — Continued. 
Genus CAMAROPHORIA, King. 
Page 21'Z. 
CaMAUOPHOKIA IIHOMBOIDAHS, Sp. IIOV. 
Fig. 25. Dorsal view of a specimen of somewhat below the average size. 
Fig. 26. Frontal view of a similar specimen enlarged ; showing the character of the marginal plication 
and the development of fold and sinns. X 2. 
Figs 27, 28, 29. Dorsal, ventral and front views of an average adult shell, possessing a sharper median fold 
and sinus, stronger plication, and showing the median septum in each valve through the sub¬ 
stance of the shell, j 
Corniferous limestone. Peru, Indiana. 
Subgenus PUGNAX, s.-gen. nov. 
l^age 202. 
PuGNAx (?) D.awsonianus, Duviclsoii. 
Fig. 30. Dorsal view of a young shell without plication. X 2. 
Figs. 31, 32, 33. Doj-sal, protile and front views of a shell with mature characters; showing the marginal 
irlication and the elevation of the beak. X 2. 
Carboniferous limestone. TVindsor, JYora (Scotia. 
Genus CAMAROPHORIA, King. 
Page 212. 
Camakophokia subcuneata, Hall. 
Fig. 34. Dorsal view of a young, but freely plicated shell; showing the shallow valves, subtriangular out¬ 
line, and long cardinal slopes. 
Figs 35, 36. Profile and front views of a mature ainl gibbous shell, showing the character of the plication 
and the broad, concave cardinal slopes. 
Fig. 37. A portion of the interioi’of the pedicle-valve, showing the spondylium supported 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. Washington county, Indiana. 
Camakophokia subtkigona. Meek tiiid Woi then. 
Fig-s. 38, 39, 40. Cardinal, frontal and ventral views of an internal cast; showing the contoui- of the shell, 
the denticulate margin of the vah'es on the bi'oad cardinal slopes, the sharply serrate anterioi' 
and lateral margins and the cavity left by the spondylium and median septum of the 
pedicle-valve. 
Chert of the Burlington limestone. Burlington, loxca. 
Figs. 41, 43. Internal casts of pedicle-valves, showing the form of the muscular impression. 
Keokuk group. Nauvoo, Illinois. 
Fig. 42. The umbonal iioi-tion of an internal cast of both valves, enlarged, the pedicle-valve being above. 
This tigure shows the cavity of the spondylium, median sei^tum 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, s.-gen. nov. 
H’age 202. 
PuGNAX Missoukiensis, SwkUow. 
Figs. 44, 45. Cardinal and iirohle views of an internal cast c>f a lai’ge specimen ; showing the contour of the 
shell, the cavities of the median septum of th.e brachial valve, the dental plates and the fore¬ 
shortened outline of the muscular area in the pedicle-valve. 
Yellow standstones of the Burlington g'roup. Burlington, Iowa, 
