a®8 
PALAEONTOLOGY OF NEW-YORK, 
Figures 13 -17 are illustrations of this species. 
Geological formations and localities. This species occurs in calcareous beds iu 
the upper part of the Hamilton group, at Eighteen-mile creek; and in the Tully 
limestone, near Ovid, in Seneca county. 
Meristella meta (n. s.). 
PLATE XLIX. 
Shell subglobose, or very gibbous, short ovate; the valves subequally 
convex, marked by a conspicuous sinus in front; hinge-line about 
two thirds the width of the shell. 
Ventbal valve very gibbous; umbo prominent, with beak abruptly 
nasute; the upper part of the valve marked by a shallow scarcely 
defined depression, which becomes a deeply marked subangular sinus 
in front. 
Dobsal valve regularly convex, gibbous in the middle and above ; ante¬ 
rior margin broadly sinuate, and the lower part of the valve marked 
by a narrow median depression. 
Sueface concentrically striated, with faint indications of interrupted 
radiating striae. In the specimens examined the shell is partially 
exfoliated, and the entire surface-characters cannot be ascertained. 
The figures 1 - 4 of Plate xlix illustrate this species. 
This fossil is referred to Mekistella from its general form, the fibrous texture 
of the shell, and the form of muscular area in the ventral valve> 
Geological formation and localitiy. In calcareous bands in the Hamilton group 
at Delphi*, Onondaga county, N. T. 
Meristella? -? 
PLATE XLVII. 
The illustrations, figures 32 and 33 of this plate, are of casts of what 
appeal to bo a species of Mebistella from the Chemung group, though 
no exterior of a similar shell has been found in the rocks of that 
formation 
