(!04 PALJBONTOLQGY OF ILLINOIS. 



breadth above the suture on the whorls of the spire; mar- 

 gined above and below by a raised line. 



Length, 0.27 inch; breadth, 0.25 inch; apical angle with 

 straight slopes; divergence, about 50 degs. 



This species belongs to the trochiform section of the genus including 

 PUurotomaria obtusispira, and P. Riddeliii, Shumard, and P. turhiitl- 

 formis, M. and W., and P. Missouriemix, Swallow (sp.) It differs from 

 all these shells, however, in being much smaller, although composed of 

 about the same number of whorls ; while it also differs from them all, 

 excepting P. obtusisplra, in having no revolving stride on the upper side 

 of its whorls, and from that species in having a more elevated spire, and 

 rather coarse, instead of " extremely fine stria3 of growth," on the upper 

 .slope of its whorls. In form and general appearance it resembles quite 

 nearly Troclms coni/ormis, de Koninck (An. Foss., pi. xxxvii, fig. 4, ^, 

 />,) but- differs in wanting the spiral stria 1 , and of course in the posses- 

 sion of a distinct but narrow spiral band. 



Locality and posit Ion Hodge's creek, Macoupin county, Illinois; low- 

 er Coal Measures. 



Genus STRAP AROLLTJS, Montfort, 

 STRAPAROLLUS (EUOMPHALUS) PERNODOSUS, M. and AY. 



StraparvUMs (Euomphalus) pernodoau^, MEEK and WORTHEX, 1870. Proceed. Acad. Nat. Sci., Phila,, 

 p. 45. 



SHELL attaining a rather large size, subdiscoidal, or with 

 the spire nearly on a plane with the upper outer edge of 

 the volution ; umbilicus broad, moderately deep, and show- 

 ing all the inner turns; volutions about five and a half, flat- 

 tened convex, and a little oblique on the broad periphery, 

 but distinctly carinated near the outer side above (the ca- 

 rina being rugose), while a little outside of the middle 

 below they are prominent and ornamented by a row of 

 moderately distinct nodes, of which about sixteen may be 

 counted on the last turn; those on the last half of the outer 

 volution becoming nearly or quite obsolete toward the 

 aperture. Upper side of each whorl flattened and sloping 



