SCIIIZOSTOMA. 361 



all the other deeply fissured Schizostomce by its quadrate form, 

 caused by the flattening of the body-whorl. In its form it 

 approaches closely to S. salebrosa, Anthony, which is, how- 

 ever, much larger and belongs, mox-eover, to the other section 

 of the genus. 



9. S. nuculum, Anthony. 



Melatoma nucula, Anthony. MSS., Reeve, Monog. t. 3, f. 19, April, 1861. 

 Gyrotoma nucula, Anthony, Brot, List, p. 27. 



Description. — Shell obtusely conical, fulvous-olive ; whorls convex, 

 smooth ; aperture narrowly ovate, a little effused at the 

 base ; fissure deep. 



Habitat. — Coosa River, Alabama. 



Observations. — Chiefly distinguished by the simplicity 

 of its characters, the shell being neither sculptured nor ^^?, 

 banded. — Hceve. 



I have not seen this species. Judging from the figure it 

 appears to me to be the same as amphim. 



10. S. cylindraceum, Mighels. 



Schizostoma cylindracea, IMighels, Bost Proc, i, p. 189, Oct., 1844. 

 Gyrotoma cylindracea, MUll., BiNNEY, Check List, No. 315. Gould, Brot, List, p. 

 27. Adams, Genera, i, p. 305. 



Description. — Shell nearly smooth, cylindrical, thick, with slight, re- 

 volving undulations; epidermis olivaceous; spire ovate-conic, eroded; 

 whorls three or four, flattened, shouldered; suture distinct; aperture 

 oval ; fissure deep and wide. 



Habitat. — Warrior River, Alabama. — Mighels. 



I can only reprint the original description of this species, 

 the shell being unknown to me. 



11. S. bulbosum, Anthony. 



Gyrotoma bulhosa, Anthony, Proc. Acad. Nat. Sci., p. 65, Feb., 18C0. Binnev, 



Check List, No, 309. BuoT, List, p. 27. 

 Melatoma hnlbosum, Anthony, Reeve, Monog., sp. 22. 

 Gyrotoma oralis, ANTHONY, Proc. Acad. Nat. Sci., p. C5, Feb., ISCO. Binnet, 



Check List, No. 325. Brot, List, p. 27. 



Description. — Shell striate, ovate, moderately thick, dark olive; 

 spire obtusely elevated, subtruncatc, four whorls only remaining; 

 whorls of the spire subconvcx; sutures very distinct, renJercd more 



