GASTROPODA. 

 PUtyovru dcprwuB.) 



wrinkl -r trrowtb; external surface uokouwn. Muscular tear horseshoe-shaped, situated a little above 



J"brmlfen nnit IcnnKfy Rtnntm Hlr r irr n[-. Vanuxrrnla bed, Belolt, Wisconsin. One of the authors 

 I cast* of Minnesota. wlm-h l> v.-ry |.i...ui,li-. i.ut as the specimen* 



lout, we cannot now verify the occurrence of the specie* In this state. 



CWJtertoiu.-UnlYerslty of Wisconsin; E.O. Ulri.-h. 



I'l.ATYOKRAS DBPRKS8UM, M. Sp. 

 IM.ATK I.XI. PI08. 65 and 66. 



This form may be only a varl.-t> ..f /'. icuoMuiiMiub. So far as the limited material at hand admit* 

 of judging, U iluT.-rs chiefly In being smaller and relatively lower. It Is scarcely probable that either of 

 UMM species really belong to I'latycmu. Perhaps they are related to the shells for which Kayser has 

 proposed the genus HerryneUa. 



Formation and JoeoKfy. Black River group, CtenodonjA bed, six miles south of Cannon Falls, 

 Minnesota. 



CbUeeffcm.-E. O. Ulrlch. 



Suborder SUBULITACEA. 



I'riniiirily this division is intended to include the Paleozoic Subulitidve and 

 Loxonrmatid<r and the more recent Kulimidte and Pseudomelaniidce. 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^E. 



Shell more or less elongate, subulate or fusiform, nearly or quite 'smooth; 

 aperture elongate, narrow, canaliculate below; no inner lip; columella involute. 



Following Lindstrftm's suggestions, we place in this family Subuliles, Conrad, 

 Huliinnrphn. Whitfield, Fusispira, Hall, and Kuchrysalis, Laube. To these we add 

 Cyrtospira, a new genus, founded on species heretofore regarded as curved forms of 



Genus SUBULITKS. < uurad. 



OOSKAD. 1847, Pal. N. V.. vol. I, p. 182; LmmTRoM, 1884, Gastropoda of Gotland, p. 103. 

 V F<Wyptemop*u, PoKTLOCK, 1843, Geol. Londonderry, p. 416. 



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 bight about as one is to four; 



