1 8 . Calvin Goodrich 



Gyrotoina lezvisii (Lea) 



PI. I, figs. i6, 17, and 18 



Schkostoma Lezvisii Lea, Proc. Acad. Nat. Sci.. Phila., XXI. 1869, p. 62; Journ. 

 Acad. Nat. ScL Phila., VIII, 1874, P- 61, pi. 21, fig. 16; Obs. Gen. Unio, XIII, 1874^ 

 p. 65. pi. xxi. fig. 16 ; Lewis. Amer. Journ. Conchol., V. 186Q-70. p. 168 ; Lewis. Fauna 

 of Ala., 1876, p. 23; Hinkley, Nautilus, XVIII, 1904, p. 41. 



Description: Shell closely striate, subcylindrical, rather thin, yellowish-brown, 

 imperforate ; spire conical, folded ; sutures very much impressed ; whorls about seven, 

 the last one large ; fissure oblique and short ; aperture large, rhomboidal, banded within ; 

 outer lip crenulate and sinuous ; columella white, thickened and twisted. 



Habitat: Coosa River, Alabama, Dr. E. R. Schowalter. 



Diameter, .5 ; length, .9 inch. — Lea. 



The fissure is oblique, shallow, 2% to 3^ mm. in depth. There is no 

 distinct girdle. A broadening or- shouldering of the whorl immediately 

 below the suture appears to serve the purpose of covering the fissure as 

 growth proceeds. In young shells this shoulder does not occur though the 

 mollusk has a well-developed fissure at this stage. 



Lezvisii is stout, ventricose to elongate and is covered with fine, sharply 

 cut folds or riblets, closely set and varying slightly in size. Growth lines 

 are fine, being crossed by minute discontinuous revolving 'lines not always 

 distinct beneath a hand lens. A few specimens are constricted upon the 

 body whorl though none taken by Mr. Smith is so much constricted as in 

 the figure of Lea's type. Color usually citrine. All the ribs seem to con- 

 tain more or less coloring matter. In young shells this shows through into 

 the aperture, giving an effect of numerous bands. As shell material is 

 deposited the finer bands or lines tend to disappear. The usually narrow 

 and elliptical aperture has a distinct sinus at its base. The columella is 

 broad and, in immature specimens, merely a wash of white above the center 

 of the aperture. The node at the top is not 'prominent. One specimen 

 has a reddish columella. The largest shell is 223^2 x 12^/2 mm. 



Half-grown specimens are conic, subangulate, slightly carinate and have 

 a pronounced sinus. The fissure is very shallow, but well-marked. 



Mr. Smith's shells, and presumably those taken by Dr. Schowalter, were 

 collected on Fort William Shoals. Hinkley (2, p. 41) gives Wilsonville as 

 another locality. This would seem to be on or within touch of Three- 

 Island Shoals. 



Dr. Lea remarked upon the resemblance of his species' to Goniobosis 

 impressa Lea. Save in regard to the fissure of lezvisii, the two shells are 

 exceedingly alike. The one, I believe, can be considered an offshoot of the 

 other. 



Gyrotoma hendersoni H. H. Smith, new species 



PL II, figs. 19, 20, and 21 



Shell: Subcylindrical, rather heavy, whorls almost flat, the last broadly rounded 

 at the base. Apex eroded, only two whor'ls remaining. The entire shell is covered with 

 low folds of varying size which tend to wave or break where new shell material has 

 been deposited after rest periods. Between the folds of the penultimate whorl the fine 



