600 PALAEONTOLOGY OF ILLINOIS. 



ture a different form, while it has a well defined spiral band occupying 

 a lower position on the whorls, and no traces of a revolving line. 



Locality and position Hodge's creek, Macoupin county, Illinois ; 

 lower part of Coal Measures. 



PLEUROTOMARIA Cox AN A, M. and W. 



PI. 28, Fig. 15. 

 Plenrotomaria Coocana, MEEK and WOKTHE.V, 1866. Proceed. Acad. Nat. Sci., Phila., p. 272. 



SHELL attaining a large size, obliquely conoid-sub- 

 trochiform, longer than wide; spire turreted, forming 

 ratlier more than half the entire length. Volutions six 

 to seven, convex, very prominent or obtusely sub-angular 

 below the middle, at which point those of the spire project 

 out over the suture ; all flattened or slightly concave above, 

 with an outward slope of about thirty-five degrees with the 

 vertical axis of the shell, from the suture to the most prom- 

 inent part, where the spiral band is placed; below this the 

 underside is rounded convex to the small, umbilical perfor- 

 ation. Suture strongly defined by the convexity of the 

 whorl just above it. Aperture subquadrate, approaching 

 sub-circular in adult shells. Surface ornamented by ex- 

 ceedingly fine, regular lines of growth, that run very ob- 

 liquely backwards, with a slight forward curve in passing 

 down the sloping upper side from the suture to the spiral 

 band at the most prominent part of the whorls; between 

 this and the umbilical perforation below they make a back- 

 ward curve. Casts also show traces of apparently much 

 stronger revolving lines near the umbilicus. 



Hight about 2.50 inches; breadth about 2.10 inches. 



. 



The specific name was given in honor of Prof. E. T. Cox, of New 



Harmony, Indiana, to whom we are indebted for the use of the best 

 specimen of the species' we have seen. 



Locality and position Iron ore beds, belonging to the lower part of 

 the Coal Measures; at Noliu's Furnace, Edmondson county, Ken- 

 tuckv. 



