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BULLETIN OF THE LABORATORIES 
pened upon a typical example of Cardinia concentrica. Many states 
of preservation conceal the teeth, but in every case the foam and char- 
acters could be exactly duplicated in specimens with the hinge so 
broken as to reveal their casts. This species labeled by Meek Palseon- 
ilo concentrica, Win., indicates the prevailing opinion in Ohio as to 
the state of the case, yet, for the present, it may be well to apply a 
a new name devoid of ambiguity. The species ranges from the shale 
below congl. I, to the concretionary lime-stones and sandy layers 40- 
50 feet below. The young are short and muculiform with few teeth. 
Note. — Paloeoneilo truncata H., is the species described by Win- 
ched as Sanguinolites marshallensis. Hall slates that the interior was 
not seen. Fig. 43, of Plate L, Pal. N. Y. , Vol. V, Part II, referred 
to P. sulcateria. Con., is probably the same, though unusually short. 
Paloeoneilo sulcateria., Con., is regarded as a synonym for P. bar- 
risi, W. and W., Nucula hubbardi. Win., and L. nuculiformis, stevens. 
This we have failed to identify or have regarded as an extreme varia- 
tion from P. elliptica. Hall’s figures, stated to have been drawn 
from Ohio specimens in part, agree with the last named species. 
Palaeoneilo attenuata, H. 
(Plate IX, Fig. 25.) 
Shell very thin, nacreous; valves slightly gaping behind, com- 
pressed, equal ; outline subrectangular, produced posteriorly, hinge- 
line straight, extending scarcely forward of the beaks, with many mi- 
nute teeth in two series, which are not in the same straight line at their 
union under the beaks, ligament apparently external ; anterior mar- 
gin strongly and evenly curved, extending nearly one-fourth the en- 
tire length forward of the beaks ; lower margin very slightly convex, 
somewhat concave at a point about one-third the length from the pos- 
terior extremity; posterior margin acutish, the lower margin curving 
slowly upward until by an abrupt flexture it approaches the upper or 
hinge margin; greatest thickness about half the height, situated about 
one-third the distance from beak to front ; a shallow depression pass- 
ing from the slight sinus of the front margin toward but not to the 
beaks, dorsal part of shell with an abrupt descent to hinge, forming a 
very narrow but abrupt umbonal slope, generally also an umbonal 
ridge nearly parallel to the hinge ; beaks small, approximate, extend- 
