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Status: Complete

26

mesial sinus broad and deep. The minute surface characters
are unknown. The specimens are casts.
This species bears some resemblance to S. macropleura of
the Lower Helderberg group, of New York, but it is propor-
tionally more gibbous, the front more regularly rounded, the
area higher, and the plications not directed so obliquely out-
wards from the beak.
Geological Formation and Locality. In limestone of the age
of the Niagara group, Racine, Wisconsin. T.J. Hale.

SPIRIFER INCONSTANS, (n.s) [penciled in Vol 1 p 69]
Description. Shell transversely elliptical, the length a little
more than half as great as the width; hinge line two-thirds as
long as the greatest width of the shell; cardinal extremities
rounded; both valves moderately convex, marked by strong,
angular, dichotomizing plications. Dorsal valve most prominent
on the umbones; mesial fold broad and simple on some speci-
mens, and on others divided into two, three, or more plications in
front; beak produced and moderately incurved. Ventral valve
larger than the dorsal; beak prominent, but little incurved;
area high; deltidium large, height and width nearly equal;
sinus broad and deep, simple or with two or more plications.
Entire surface marked by strong, distinct, radiating striae.
The specimens are casts of the interior and exterior.
This species may be readily distinguished from others by the
strong, angular, bifurcating plications, the number of which
vary in different individuals; some being nearly simple, having
but four or five on each side of the mesial fold, while others
have nearly double that number on the front margin. The
number of plications on the mesial fold and sinus are subject
to the same variation.
Geological Formation and Locality. In limestone of the age
of the Niagara group, Racine, Wisconsin. Dr. Hoy, T.J.
Hale, James Hall.

TELLINOMYA INFLATA, (n.s.) [penciled in Vol 1 p 38]
Description. Shell of medium size, extremely gibbous, and
inflated at the middle of the sides, abruptly attenuate towards
the posterior end; the length a little greater than the breadth,
and the thickness a little less; the hinge line, from a little
anterior to the beak to the posterior end of the shell, is nearly
straight, the anterior end obliquely truncate above the middle.
the basal margin strongly and regularly rounded from the ante-

[pencilled in + S. Racinensis, Mc Ch}

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