238 PALEOZOLC PALEONTOLOGY, 
SPIRIFER VANUXEMI Hall, var. MINOR n. var. 
Plate XXI., Figs. 41-42. ; ’ 
1859. Spirifer vanuzemi Hall, Pal. N. Y., vol. III, p. 198, pl. 8, 
figs. 17-25. 
Description.—Shell small, subelliptical in outline, the hinge-line a 
little shorter than the greatest width of the shell. Umbo of pedicle 
valve prominent, beak incurved over the moderately high, concave, ill- 
defined cardinal area; mesial sinus rather broad, rounded in the bot- 
tom, the lateral slopes marked by three broadly-rounded plications on 
either side. Brachial valve depressed-convex, with a rounded median 
fold, which is but slightly elevated above the plications on either side. 
Surface of both valves marked by concentric lines of growth. 
‘The dimensions of the largest specimen of the pedicle valve are: 
width, 7 mm.; length, 5.5 mm., and convexity, 3 mm. 
Remarks.—This little shell is not abundant in the Decker Ferry 
fauna. It seems to agree closely with Spirifer vanuxemi Hall, of the 
Manlius limestone fauna, except in being smaller and in having the 
concentric markings less conspicuous. 
CYRTINA MAGNAPLICATA DN. Sp. 
Plate XXI., Figs. 46-49. 
Description.—Pedicle valve subpyramidal with a strong median 
septum, the beak more or less incurved over the elevated, concave, 
cardinal area, which is not sharply defined on the margin. Mesial 
sinus sharply defined, subangular in the bottom; lateral slopes marked 
by four strong, angular plications on each side of the sinus, with some- 
times an additional fainter one near the cardinal margin, only the first 
two of which reach the point of the beak. Brachial valve depressed- 
convex, subelliptical in outline, with a mesial fold and three or four 
subangular plications on either side, all rising to about the same ele- 
vation. | 
The dimensions of the best preserved pedicle valve are: width along 
the hinge-line, 16 mm.; length from beak to front margin, 14 mm. 
