GASTROPOD A—SUBULITIDJE. 



697 



Stones River and Black River of Minnesota, 

 Tennessee, Kentucky, and Canada. 



297. S. nanus Ulrich. (Fig. 100 1, b.) 



Ordovicic. 



Minute, not over 1 5 mm. high, very acute apex, 

 and narrow elongate aperture not quite the length 

 of the spire. 



Stones River of Tennessee and Kentucky. 



LXXXV. Fusispira Hall. 

 Differs from Subulites in the heavier shell, broader 

 and shorter aperture, more rounded whorls, and 

 deeper sutures. Ordovicic. 



298. F. inflata M. and W. (Fig. 1002, a.) 



Ordovicic. 

 Short, concave-spired, whorls embracing to am- 

 bitus, body whorl large, inflated. 



Trenton of Minnesota, Wisconsin, and Illinois. 



299. F. subbrevis U. and S. (Fig. 1002, b.) 



Ordovicic. 

 Thicker spire, whorls less embracing, body whorl 

 large and long, but not inflated. 

 Trenton of Minnesota and Iowa. 



300. F. subfusiformis Hall. (Fig. 1002, c.) 



Ordovicic. 

 Slender, whorls gradually enlarging, convex, 

 body whorl not proportionately larger; apical angle about 25 °. 

 Trenton of Minnesota, Kentucky, New York, and Canada. 



301. F. convexa U. and S. (Fig. 1002, d.) Ordovicic. 

 Like preceding, but apical angle 33 to 37 ° ; whorls more 



convex, shorter, and with deeper sutures ; aperture relatively 

 wider ; occasionally with distant revolving spirals. 

 Trenton of New York and Minnesota. 



302. F. angusta U. and S. (Fig. 1002, e.) Ordovicic. 

 More slender, less closely-coiled, and with longer and less 



convex volutions than in F. subfusiformis. 

 Trenton of Minnesota and Kentucky. 



Fig. 1 00 1. 

 Subulites regula- 

 rise S. nanus. 

 (After Ulrich and 

 Scof.,Pal. Minn.) 



