PLATE Lm— Continued. 



CcELOspiRA Camilla, H.ill. 



Figs. 34-36. DonuJ, profile %nd ventnd views of a typical sfiecimen ; showing the contour and siirface char- 

 acters. X 2. 



Vig. 37. The interior of the brachial valve j showing the elevated and somewhat recurved hinge- plate. X 4. 



Fig. 38. The interior of a i>e<iicle valve ; showing the open delthyrinin. the teeth and niuscMiIar impres- 

 Bions. X 4. 



Coniiferous limestone. Caledonia, N. Y. 



Vig. 39. The interior of a jHidicle- valve ; showing characters similar to those of the prece<Ung figure. X 2. 



Fig. 30. The exterior of a jiedicle-valve. X i. 



V\g. 31. The interior of a brachial valve ; showing the hinge-plate and median ridge. X 3. 

 Corniferous limestone. Lf Rdy, N. Y. 



C(ELO.SPIRA ACUTIPLICATA, Coilfad. 



PigB. 83-3.^. Dorsal, profile, ventral and frontal views of the exterior of a typical specimen j showing the 

 contour, coarse, sharp plication and concentric lineation of the valves 

 Cornifei-ous limestone. Jainesville, N. Y. 

 Pig. 36. The interior of a i>ortion of the brachial valve ; showing the recurved hinge-plate, deep dental 



sockets and median ridge. X 3. 

 Fig. 37. The exterior of a pedicle-valve slightly imjiei-fect about the margins. X '■i- 

 Fig. 38. The interior of the same specimen ; showing the open delthyrium and teeth. X 2. 



Corniferous limestone. Waterlmt, N. Y. 

 Fig, 39. The interioi- of a brachial valve with faint lateral plications ; showing the hinge-plate, dental 

 sockets and median ridge. 



Ciorniferous limestone. Sangerfield, N. Y. 



Genus LEPTOCCELIA, Hall. 

 Leptocoxia flabellites, Hall. 



Pigs. 40-42. Dorsal, ventral and protile views of an average example ; showing the contour and sui-face 

 characters. 



Fig. 43. The interior of a brachial valve ; showing the structure of the hinge-plate, dental sockets and 

 muscular area. 



Vlg. 44. A profile of a large shell ; showing the plano-convex contour. 



Kg. 4S. The interior of a brachial valve, somewhat imperfect about the margins j showing a slight varia- 

 tion of the charactei's as represented in fig. 43. 



Fig. 46. The cardinal region of another brachial valve, enlarged ; showing the excavation of the cardinal 

 process on either side of a median ridge, and the projection of the crural lobes. X 2. 



Fig. 53. The interior of a i5e<licle-valve ; showing the open delthyrium, teeth, adductor and diductor scars. 

 Oriskany sandstone. Owmherland, Maryland. 



IjEPI()C<klia fimbkiata, Hall. 



Fig. 47. Dorsal view of the jwsterior portion of the shell ; showing the fimbria of spinules or testaceous 

 processes extending from between the cardinal margins. X 3. 



Fig. 48. A profile of a brachial valve; showing the elevation of the cardinal process and crura. X 3. 



Fig. 49. Cardinal view of a brachial valve ; showing the elevation of the cardinal process, socket-walls 

 and crura, and the foi-eshortened cardinal spinules. 



Rg. 50. Dorsal view of conjoined valves ; showing the exterioi' charactei-s and the cardinal spinules. X 3. 



Fig. 51. The interior of a brachial valve; showing the structure of the articulating apparatus, the char- 

 acter of the muscular area, an(i the marginal spinules which are inserted upon this valve. X 2. 



Ftg. 63. The interior of a pedicle-valve ; showing the foramen, teeth and muscular area. X 2. 



Ptga. 54, 55. Interiors of pedicle-valves ; showing some variation in the retention of the strtictural featui-es. 

 X3. 



Oriskany sandsUme. Ou/mberland, Maryland. 



