DEVONIAN FAUNAS. 307 
CYRTINA HAMILTONENSIS Hall. 
Plate LII., Fig. 5. 
1867. Cyrtina hamiltonensis Hall, Pal. N. Y., vol. IV., p. 268, pl. 27, 
figs. 1-4, pl. 44, figs. 26-33, 38-52. 
Description.—Imperfect specimens of a species of Cyrtina occur at 
both the Newfounland and the Greenwood lake localities of this for- 
mation, which seem to be identical with C. hamiltonensis. The pedicle 
valve is subpyramidal in form, with a high, nearly-flat cardinal area, 
and in the internal casts a slit representing the median septum reaches 
from the beak more than half way to the front of the valve. The 
mesial sinus is well defined, smooth, rather shallow and rounded in 
the bottom, and on each lateral slope there are five or six simple, 
rounded plications. The brachial valve is depressed-convex, with the 
mesial fold flattened and but Jittle elevated above the general surface 
of the valve; the plications upon the lateral slopes resemble those of 
the opposite valve. 
The dimensions of the best pedicle valve observed are: length from 
beak to front margin, 9 mm.; width, 11 mm.; height of area, 5 mm. 
Remarks.—The only specimens of this species which have been ob- 
served are imperfect internal casts, but they exhibit the characteristics 
of this common Devonian species. 
ANOPLOTHECA ACUTIPLICATA (Con.). 
See, also, pp. 370 and 383. 
The specimens of this species in the Newfoundland grit do not differ 
materially from those found in the Onondaga limestone of the Dela- 
ware valley, except in being preserved in sandstone in the condition 
of internal casts. They somewhat resemble the Oriskany species, A. 
flabellites, but are constantly smaller. 
