182 
PALAEONTOLOGY OF NEW YORK. 
Pholidops calceola, sp. nov. 
PI,ATE IV I, FIG. 30. 
Shell small. Outline subelliptical, the posterior margin being narrowed by 
the extension of the beak, which is long and acute, slightly elevated above 
the plane of the margin. External surface marked by concentric lamellose 
growth-lines, which extend about the posterior side of the beak. Muscular 
area central; posterior margin divided into a broad central and two lateral 
arches, from the latter the outline extending in a regular curve to the ante¬ 
rior margin. Adductor scars sharply defined. The dorsal (?) valve only is 
known. Length of the original specimen, 3.5 mm. 
Corniferous limestone. Falls of the Ohio. 
Pholidops patina, sp. nov. 
PLATE IV I, FIGS. 27-29. 
Shell comparatively large; outline elongate-ovate or elliptical. Length to 
width as 3 to 4. Apex posterior. Surface covered with lamellose con¬ 
centric growth-lines, which are crossed by fine, interrupted radiating striae. 
The interior of the ventral (?) valve has the anterior and posterior adductors 
well defined, the latter being lobate. The median scars are well developed 
and the parietal impression acutely angled at the center. In the opposite 
valve the anterior edges of the muscular area are sharply elevated, both pairs 
of adductor scars prominent, and the parietal scar extended posteriorly. 
Corniferous limestone; from boulders of decomposed chert. De Cewville, 
Ontario. 
