GASTROPODA. '.''.'"> 



l.rupla.l 



v.m.-what <it>li.|uely, nearly twice as much of It being visible la a view of the upper ldc than Is 

 MO In a basal vl.-w. It Is to be distinguished ..n.v . n th.> ut specimen*, but we hare at least rlfty 

 us showing It very clearly. The Inn.-r lip In almost vertical In the Trenton variety of the species 

 and always more nearly so than In the Utlca form. 



species rarely, if ever, exceeds 16 mm. In diameter, the average for most localities being 11 or 

 rj mm. The Maquoketa shales types are commonly less than 10 mm. In diameter. Aside from the fact 

 that It is considerably smaller there Is little to distinguish L. mfculo from L. pngne Billings sp. They 

 arc doubtless closely related species. 



formation and locality. Trenton group, Buiyln, Danville and Frankfort, Kentucky; Utlca group 

 (Maquoketa shales) at various localities In Minnesota, Wisconsin, Illinois and Iowa, associated with 

 Kximtfa ftcundu; also In Ohio and Kentucky, where there Is reason to believe that It ascends Into th. 

 Lorraine group. 



CWJeteiom-B. O. Dlrlch. 



LlOSPIRA ABRUPTA, tl. 8p. 



PLATE L\X Ml. FIOS.4S-*. >i > *""~'*3 ^ 



A small species like the preceding but with the spire relatively less elevated and not entirely 

 smooth at the sutures, the outer edges of the Inner whorls projecting Just enough to be noticed readily 

 by the naked eye. The band Is also more distinct, especially upon the upper side where It reminds one 

 considerably of the concave band of an Eotomaria; then It Is also sharper on the edge, while the lower 

 half of the band Is usually much more distinct. The umbilicus Is not filled but extends up to the 

 .ipi.-al whorl, showing all the whorls within ; Its edge Is sharply angular, the sides nearly vertical, while 

 Its width equals something like a fourth of the greatest diameter of the shell. The base la a trifle 

 higher than the spire, the basal slope, from the periphery to the edge of the umbilicus, gently convex; 

 the aperture is triangular, IU width slightly exceeding the bight. Aside from the peripheral band, the 

 surface appears to have been without markings of any kind. There are four whorls without counting 

 the minute nucleus. 



The largest of four specimens from Minnesota, belonging to this or a closely related species, has LtAuA. 

 a width of &5 mm. The width In about one hundred specimens from Tennessee varies from 7 to 10 mm., /&Jfo 

 and in nine-tenths of these from 8 to 9 mm. The Minnesota specimens doubtfully referred here differ froBO 

 the Tennneseeand Kentucky types of the species In the more rapid expansion of the whorls, three sufficing T? 1 ' 

 where it requires four In the latter, and in having a relatively higher spire. In both of these points x^ /6v 

 they agree with L. mieula Hall sp., and we would refer them to that species were It not that they have ^/ 



an open umbilicus. 



formation and locality. Stones River group, Murfreesboro, Tennessee; High Bridge, Kentucky. 

 Two of the Minnesota specimens referred to are from the limestone at Minneapolis, the others from 

 the Black River shales at Cbatfleld. 



CbUKtfon.-K. O. Ulrich. 



LIOSPIRA VITRUVIA 



PLATE LXIX. KIOS. t-9. 



I'leumtomaria rilrurta HILLINGS, 1806, Pal. Fosa., vol. 1, p. IT I. 



I'Uurotamaria (or Raphutoma) lenticvlarii (part.) of numerous American authors. 



rums of this well marked species are not known to exceed 30 mm. in diameter, a good average 

 being about 25 mm. The bight Is about half of the width. The upper side of the last whorl Is 

 frequently a little concave because of a slight elevation of the peripheral band. The umbilicus Is open 

 hut varies somewhat in size, Its width being often not more than a fourth, at oth.-r times quite 

 a third of the greatest diameter of the shell. The principal peculiarities of the species occur on the 

 under side. Here we have first the open umbilicus with IU angular margin and flattened sides; and 



