186- Cincinnati Society of Natural History. 
CTENOBOLBINA PUNCTATA, N. sp. 
Te XT SUS a ane 
Size of right valve: Length, 1.5 mm.; height, 1.0 mm.; thick- 
ness, 0.3 mm. , 
Carapace moderately convex, subovate, with the ends nearly 
equal, the anterior one very slightly the narrowest, the back 
straight, rather long, the dorsal angles about 110°; outline of 
ventral two-thirds semicircular. Flange or frill of moderate width, 
best developed at the ventral edge, becoming obsolete gradually 
before reaching the dorsal angles. Posterior sulcus deep, sharply 
defined, nearly vertical, slightly curved. Anterior sulcus wanting, 
but there is an oblique swelling, forming the most prominent por- 
tion of the valves, in the anterior half. Posterior lobe large, but 
of more ovate shape than in the typical Cincinnati species. Sur- 
face punctate. 
This is an unquestionable Czenobolbina, with relations to C. ciliata 
var. emactata, (ante p. 109; p. 8 of reprint), but distinguished 
from that and all the other species known by its punctate surface. 
Comparison with the figures on plate VII, will reveal other differ- 
ences. 
Position and locality: Shales of the Niagara group, Lockport, 
INAa 
CTENOBOLBINA PAPILLOSA, Nn. sp. 
Plate XV TUES. 8G, OG 
Size of left valve: Length with frill, 1.43 mm.; height with 
frill, 0.87 mm.; thickness, o.4 mm.; length without frill, 1.32 mm.. 
height, 0.76 mm. 
The valves of this species have the shape generally met with in 
Ctenobolbina. Lobation bijugate. The posterior sulcus, though 
well marked and deep, is comparatively short, causing the posterior 
lobe to be less distinct than usual. Central lobe large, prominent; 
anterior sulcus narrow but well-impressed, vertical, like the pos- 
terior sulcus extending but little more than half across the valve ; 
anterior lobe small. Frill or flange’ well-developed. Surface 
strongly papillose, with the papille largest on the lobes. 
This well-marked form is distinguished from the Silurian species 
