GASTROPODA. 1069 
Platyceras depressum.] 
wrinkles of growth; external surface unknown. Muscular scar horseshoe-shaped, situated a little above 
the midhight. 
Formation and locality.—Stones River group, Vanuxemia bed, Beloit, Wisconsin. One of the authors 
believes he collected casts of this shell also in Minnesota, which is very probable, but as the specimens 
have been mislaid or lost, we cannot now verify the occurrence of the species in this state. 
Collections.— University of Wisconsin; HE. O. Ulrich. 
PLATYCERAS DEPRESSUM, %. Sp. 
PLATE LXI, FIGS. 55 and 56. 
This form may be only a variety of P. wisconsinensis. So far as the limited material at hand admits 
of judging, it differs chiefly in being smaller and relatively lower. It is scarcely probable that either of 
these species really belong to Platyceras. Perhaps they are related to the shells for which Kayser has 
proposed the genus Hercynella. 
Formation and locality—Black River group, Ctenodonta bed, six miles south of Cannon Falls, 
Minnesota. 
Collection.—H. G. Ulrich. 
Suborder SUBULITACEA. 
Primarily this division is intended to include the Paleozoic Subulitide and 
Loxonematide and the more recent Hulimide and Pseudomelaniide. There are other 
Mesozoic and living shells that are more or less obviously related to the families 
mentioned and which might perhaps be advantageously classed with them, but it 
seems to us too early to attempt either a characterization of the suborder or an 
enumeration of its probable contents. 
Family SUBULITID A. 
Shell more or less elorgate, subulate or fusiform, nearly or quite smooth; 
aperture elongate, narrow, canaliculate below; no inner lip; columella involute. 
Following Lindstrém’s suggestions, we place in this family Swbulites, Conrad, 
Bulimorpha, Whitfield, Fusispira, Hall, and Euchrysalis, Laube. To these we add 
Cyrtospira, a new genus, founded on species heretofore regarded as curved forms of 
Subulites. 
Genus SUBULITES, Conrad. 
Subulites, CONRAD, 1847, Pal. N. Y., vol. i, p. 182; LinpsrRém, 1884, Gastropoda of Gotland, p. 193. 
? Polyphemopsis, PORTLOCK, 1843, Geol. Londonderry, p. 415. 
Shell thin and unadorned, slender, subulate or somewhat fusiform in outline; 
whorls high, flat or very slightly convex on the outer side; suture linear, sometimes 
scarcely distinguishable, in no case greatly modifying the almost even slope of the 
slender spire; aperture elongate, narrow, acuminate above, widest and somewhat 
truncated below, much higher than wide, the width and hight about as one is to four; 
