300 AMERICAN JOURNAL 



10, Lea. 

 a. jihell smooth or only slightly tuherculate. 



1. I. fluvialis, Say. Figs. 1 — 6. Fusiform, spire conical, 

 body whorl gibbous; lengthened into a canal at base; smooth, 

 or slightly nodulous upon the periphery of each whorl, those 

 of the spire nearly concealed. Light yellow, brown, olive, or 

 nearly black, in the latter case dull red within the aperture; 

 sometimes banded. Solston River, W. Va., and E. Tenn. 



Figs. 1, 2, 3 are typical, 4 is verrucosa, Reeve, 5 and 6 are tenebrosa, 

 Lea. 



2. I. inermis, Anth. Figs. 7, 8. Conical, smooth, thick, 

 spire elevated, flattened ; body whorl concave above the 

 periphery, which is rounded, scarcely angulate, without tuber- 

 cles. Light brown to dark olive, bluish or reddish within, 

 sometimes banded. Same locality as No. 1. 



Larger tiian No. 1, with heavier texture, more regularly fusiform. Fig. 

 7 is typical, 8 is lurida, Anth. 



h. Shell spinous, or Tnuch tuherculated. 



3. I. spinosa, Lea. Figs. 9 — 14. Turrited, spire conical, 

 periphery with large spines or elongated tubercles, covered, or 

 visible on the spire; whorls seven. Light brown to dark 

 olive, sometimes banded within. Same locality. 



Figs. 9, 13, 14 are typical, 11 is recta^ Anth., 12 is gibbosa, Anth., and 

 10 is rhombica, Anth. 



4. I. brevis, Anth. Figs. 15, 16. Ovate, conic, short and 

 heavy; canal short and wide; tubercles compressed, large, not 

 much elevated transversely. Light brown, frequently banded 

 within. Same locality. 



I. spirostoma, Anth., (Fig. 16) is merely a distorted growth of this 

 species. 



5. I. turrita, A7ith. Fig. 17. Conic, narrow, elevated, 

 spinous; spines rather short and heavy, about 7 on a whorl; 

 whorls 9; aperture pyriform, small, one-third the total length, 

 canal short and wide; spire much lengthened; apex acute. 

 Horn-colored or greenish, handsomely banded within. Same 

 locality. 



This beautiful and rare species is readily distinguished from the others 

 by its very narrow, elongated form. 



