928 THE PALEONTOLOGY OF MINNESOTA. 



lOurlnaropsIs phalora. 



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. cunulce. 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 Eiver group, but this is probably an error. 



Collection. E. O. Ulrich. 



CARINABOPSIS 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. cunulw 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 

 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, Rhinidictyaand Ctenodonta beds, St. Paul, Minneapolis 

 Chatfleld, Minnesota. 



Colkctions. E. O. Ulrich; original types in the cabinet of the geological department of the Uni- 

 versity of Minnesota. 



CARINAROPSIS ACUTA, n. sp. 



PLATE LXII, FIGS. 8-9. 



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 augulation 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 Natural History Survey of Minnesota; E. O. Ulrich. 

 Muxeum Register, No. 7".:t4. 



