..i-oiiA. 



at PlrorU,rllJ^ 1 



the c i iv n inference of the last whorl; band narrow, convex, the lunulip not much 

 cur\' -tronj; aii-1 prominent at regular intervals, giving the band a crenulated 



..i toothed appearance; columellar lip scarcely callous, reflected and forming a sort 

 of false umbilicus; Mirfaco ornamented with -piral ridges; lines of growth moderately 

 curved backward on the upper side of the whorls, nearly vertical beneath the band. 

 Typo, /'/. munsteriana I 'e Kmiinck. 



This tfenus i- represented by three good species in the Carboniferous deposits 

 of America, vi/ : /'/. taljulti/,1 Conrad, /'/. subscalari* Meek and Worthen, and PI. 

 sptciosa M. and W. We have before us a small undescribed species from the 



man of Ohio that probably belongs here. The Worthenias remind one greatly 

 of certain Lower Silurian types of Lophospira, particularly of the Bicincla section 

 and L. knoxtillensis, and it is highly probable that they will be traced back to some 

 member of that genus. We think further that they will be brought into connection 

 with the I'pper Silurian 1'hanerotremas. For the present they are readily 

 li-tiMjiiUhfl from the latter by their higher spire, more gradually increasing 

 volutions, and different band. From Isophospira they are separated by the denticu- 

 late band, strong spiral ornamentation and in having a true slit 



V. LIOSPIRA, n. gen. Shell sublenticular, the spire low, depressed conical, 

 almost smooth, the sutures very close, scarcely distinguishable; volutions aubrhom- 

 boidal in section, flat, gently convex or slightly concave above, sharply rounded at 

 the periphery, convex below, and not infrequently angular at the edge of the 

 umbilicus. The latter is usually present but may be filled entirely by an extension 

 from the inner lip, in other cases it may be open during the younger stages only. 

 Aperture deeply notched; band scarcely distinguishable as such, wide, situated on 

 the narrow outer edge of the whorls though chiefly upon the upper side. Surface 

 markings very delicate, rarely preserved, consisting generally of exceedingly fine 

 transverse lines bending strongly backward on the apical side to the peripheral 

 hand over which they continue with little interruption to sweep sharply forward 

 again on the lower side. Faint revolving lines occasionally observed. Types, 

 '"/./ Hall. /'/. . nn Billings. 



VI tu, n. gen. (Ulrich.) Shell subtrochiform, regularly conical, base 



nearly Hat. -uture >hallow; umbilicus usually of largo size; mouth subqnadrate, the 

 inner lip but little reflected and scarcely thickened, the outer with a wide notch 

 but no slit, the upper projecting l>eyond the lower: whorls numerous, enlarging very 

 gradually, sharply angular at the lower edge; band not sharply defined, of moderate 

 width, lying entirely upon the upper side of the peripheral edge; on the upper side 

 of the whorls the lines of growth are fine and strongly curved backward from the 



;re to the band; on the lower side, where they are usually somewhat stronger, 



