ORTHONOMAA, Hatt. 
Page 814. 
Zyeosrrra (ORTHONOM®A) ERRATICA, Hall. 
Fig. 34. The exterior of a pedicle-valve; showing its contour and fine surface 
plication. 
Hudson River group. Hamilton, Ontario. 
Fig. 35. The interior of a pedicle-valve; showing the open delthyrium, the 
deep posterior muscular scar, the lateral impressions at the sides of 
this scar and over the median portion of the valve, traces of the 
primary lamellz. 
Fig. 36. An internal cast of the pedicle-valve; showing the muscular scars. 
Xx 2. 
Fig. 37. The interior of the brachial valve ; showing the bilobed cardinal pro- 
cess, muscular and vascular impressions. 
(Figs. 35 and 37 from gutta percha squeezes.) 
Hudson River group. Erratic blocks of central New York. 
CLINTONELLA, Hatt. 
Page 814. 
CLINTONELLA VaGAaBuNDA, Hall. 
Fig. 88. The interior of the umbonal portion of the brachial valve ; showing 
the divided hinge-plate and low median ridge. * 3. 
Figs. 39,40, 41. Ventral, profile and dorsal views of a specimen from which 
the brachial valve is removed. 
Fig. 42. The interior of the umbonal region of conjoined valves, viewed from 
in front ; showing the mode of articulation and the bilobed cardinal 
process. X 3. 
Figs. 43, 44. Ventral views of two internal casts; showing the muscular area 
crossed by the plications of the shell. 
Clinton group. Drift of western New York, 
235 
