928 THE PALEONTOLOGY OF MINNESOTA. ee Ar 
aperture not reflected, causing an unusual depth between the lip and the edge of 
the septum; edge of septum scarcely thickened, the whole outer surface of septum 
nearly smooth. In other respects like C. cunule. The great excavation of the septum 
is the principal peculiarity of the species. 
Formation and locality.—Top of the Trenton group, near Danville, Kentucky. The original types 
of the species are said to have come from the Hudson River group, but this is probably an error. 
Collection.—H. O. Ulrich. 
CARINAROPSIS PHALERA Sardeson. 
PLATE LXII, FIGS. 14—18. 
Carinaropsis (or Bellerophon) phalera SARDESON, 1892, Bull. Minn. Acad. Nat. Sci., vol. iii, no. 3, p. 336. 
This form is very near C. cunule Hall, the only differences that we can now 
see being the apertural margin which is less reflected and scarcely truncated 
posteriorly, giving a more nearly circular outline and greater depth to the concavity 
oes 
of the septum. Mr. Sardeson mentions “indistinct radiating folds on the dorsal 
surface” of one of his specimens (a cast), but we have failed to notice anything of 
the kind. 
Formation and locality.—Black River group, Rhinidictya and Ctenodonta beds, St. Paul, Minneapolis 
Chatfield, Minnesota. 
Collections —E. O. Ulrich; original types in the cabinet of the geological department of the Uni- 
versity of Minnesota. 
CARINAROPSIS ACUTA, ”. Sp. 
PLATE LXII, FIGS. 6—9. 
Shell very delicate, the largest about 27 mm. in length, but the majority of the 
specimens before us, perhaps because of imperfection, are only from 3 to 11 mm. in 
length. Volutions about three, the inner ones very small, greatly compressed, and 
very sharp on the dorsum, the last expanding very rapidly. As the dorsal angle 
becomes gradually less acute and the rate of expansion of the volutions increases, 
the aperture changes from triangular to subcircular. Septum comparatively short, 
the edge much within the plane of the apertural margins. Posterior lip not reflected. 
Surface, so far as observed, quite smooth. 
This differs from the preceding species in the greater compression and much 
sharper dorsal angulation of the inner whorls, and in the much shorter septum. 
Formation and locality.—Black River shales, Rhinidictya and Ctenodonta beds, Cannon Falls, and 
near Fountain, Minnesota. 
Collections—Geological and Naturai History Survey of Minnesota; BH. O. Ulrich. 
Museum Register, No. 7534. 
