Israelsky, new species
figures 1, 2, 3, 4
Test tumid, thick walled; outline from above ovoid; ambitus rounded;
madreporic system posterior to the center; petals reach about one-half
the distance to the ambitus, tending to close distally,
interporiferous areas strongly raised; greatest width of petals about
one-third length; anterior unpaired petal slightly longer than paired
petals, paired petals subequal; viewed from the side the outline is
strongly arched above, higher anteriorly than posteriorly, and concave
below; the peristome lies in a deep transversely elongate groove
slightly behind the center; periproct about two-thirds the distance
from peristomal groove to ambitus; surface apparently ornamented with
stnall scrobiculate tubercles.
5210, 5211, Mus. Calif. Acad. Sci., collected by Lawrence G. Putnam.,
12 kilometers northeast of Abasola, Tamaulipas, Mexico; upper Eocene.
Topotypes: 5214 and 5215, C. A. S. type collection.
Plasto-Syntypes: Nos. 422, 423, San Diego Society of Natural
History type collection. Idiotypes: 424, 425, S. D. S. N. H.
The new species appears to be more closely related to Oligopygus
haldermani (Conrad) 1 than to any other thus far described. It may
be readily distinguished from that foret by its more anterior
periproct. The posterior position of the madreporic system appears to
separate it from other species of the genus.
The species may be the one found by Wise and Cavins in this same
district, but not named by them.