34 
BULLETIN OF THE LABORATORIES 
concentric, more or less wavy grooves and striations. Length, 25 
mm., height, 23 mm. 
It is not possible to strictly define this species but it is sufficiently 
distinct from any of the associated species. 
Concretionary shale seventy feet below conglomerate I, near Lyon 
Falls, Ashland Co. 
CRENIPECTEN CANCELLATUS. Her. 
(Plate V, Fig. 3.) 
[Vol. Ill, p. 54, Plate XII, Fig. 7.] 
Full-grown specimens of this species are less orbicular, and the 
right valve makes it obvious that our species is not a Lyriopecten but 
probably Crenipecten, though the hinge is still unknown. 
Right valve closely resembling in outline that of Streblopteria 
media, but less convex and with a larger posterior ear. Surface mark- 
ed, as in the opposite valve, by sharp, fine, and very numerous con- 
centric and radiating striae, the radiating striae becoming very coarse 
on the anterior. 
CRENIPECTEN CREN ISTRIATUS, Meek. 
(Plate V, Fig 14.) 
A considerable suite of specimens permits little doubt that the 
various forms of large Pecten-like shells of the upper Waverly all be- 
long in the assemblage named as above by Meek. We have not in- 
deed encountered any individuals with the outline as drawn in the 
Ohio Palaeontology, but although these figures are not expressly said 
to be restorations, yet that this is the case is implied in the following 
remarks: “It is remarkable in having only a comparatively shallow 
rounded sinus under the anterior ear of the flat right valve, where it is 
usually deep and angular in species of this genus, while in the left it is 
deeper and more angular, though none of the specimens are in a condition 
to show its exact form. ’ ’ 
Considerable variation is encountered in shells from different hori- 
zons. Those found only a few feet above conglomerate II most near- 
ly resemble the figures of Meek, but the left valve has the posterior ear 
more strongly produced and larger, while the anterior ear is much 
larger and the margin below the sinus is produced and abrubtly angu- 
