312 
Aug. F. Foerste 
numbered 1136-1, in the American Museum of Natural History, 
in New York, I have chosen the one showing the trilineate periph- 
eral band to best advantage as the type, since this specimen un- 
questionably furnished the material for Fig. 2c on plate 83, ac- 
companying Halhs description. A third specimen occurs in the 
same rock as what I regard as the type of Ormoceras crebriseptum, 
namely figure 26, on plate 87. The vertical striae of this Ormo- 
ceras belong only to the exfoliated interior of the shell, and the ap- 
pearance of the surface is unknown. The trilineate peripheral 
band of the Lophospira ahhreviata is well shown, and there is a 
trace of a revolving angulation very much farther down than in 
Lophospira lirata, Ulrich. There is no trace of an angulation on 
the upper slope. 
Shells of this type, with subrotund whorls and trilineate periph- 
eral bands, the three lines nearly subequal, appear sufficiently 
distinct from the typical forms of Lophospira to receive a dis- 
tinct designation. For this reason the term Ruedemannia is 
here proposed, in honor of Dr. Rudolph Ruedemann, as a 
slight recognition of his monumental labors on Paleozoic fossils. 
As a type of this genus, Lophospira lirata, Ulrich, from the Eden 
formation at Cincinnati, has been selected, because the New York 
species here described appears more closely related to the Lophos- 
pira lirata of Ulrich than to the Pleurotomaria rohusta of Lind- 
stroem. The presence of revolving striae is not regarded as 
essential. I assume, in the absence of further data, that the Lo- 
phospira lirata of Ulrich is identical with the Pleurotomaria ohio- 
ensis of James, a species from the Cincinnatian of Ohio, but from 
a horizon not designated by the author. The type of Lophospira 
lirata, Ulrich, forms No. 45904 in the collections of the U. S. 
National Museum. 
45. Pterotheca cf. attenuata, Hall 
{Plate II, Fig. S) 
A small species of Pterotheca, apparently belonging to the 
Pterotheca attenuata group. Lateral margins gently convex, 
rounding more strongly into the posterior and anterior margins, 
resulting in a rounded quadrangular outline. Shell moderately 
convex, excepting at the carina which rises strongly above the 
general convexity of the shell. In a specimen 20 mm. wide and 
