1 6 ' Calvin Goodrich 



straight fissures. The difference did not seem to be a matter of age. The 

 depth of fissure is from 6 mm. in half-grown shells to lo mm. in old. The 

 girdle is yellow, rather wide, and is well-marked in nearly all specimens. 



The species is probably the most robust of the genus. The largest 

 specimen in the Alabama collection measures 26^ x 13^ mm. The base 

 is sub-angular up to three-fourths of the growth. In adults, it is rounded. 

 The folds are low, not always regularly-spaced, and are stoutest in young 

 shells. Occasional smooth shells have been taken. A distinct tendency to- 

 ward plication is noticeable upon the upper whorls. The nearly miscroscopic 

 sculpture consists of fine growth lines, crossed by discontinuous, wavy trans- 

 verse lines. The color is buckthorn-brown to deep olive. Two bands of 

 equal width, at top and base respectively, and a third band, much wider, at 

 the periphery constitute the commonest banding formula. In many speci- 

 mens coloring matter is deposited in the base of the folds and this shows 

 in the aperture as bands or lines. The aperture is elliptical rather than 

 ovate. The columella is white, not very wide, thinning above the center into 

 a bluish-white wash with a porcelainous node at the mouth of the fissure. 

 The sinus is distinct. The outer lip is sharp-edged, crenulate, slightly 

 sinuous. 



Young shells are ovate, sub-angulated, plicate upon the post-embryo 

 whorls ; the fissure straight, not wide ; the columella narrow, yellowish- 

 white ; the sinus having a shallow channel. Seven or eight whorls are indi- 

 cated for the adult specimen. 



The range of alahmnensis is from Peckerwood Shoals, Talladega County, 

 to Duncan's Riffle, Chilton County. 



Peckerwood Shoals shells are wider in proportion to height than speci- 

 mens from other known localities and they show, more than these others, 

 the relationship of alabamensis and cariniferum Anth. A varietal name 

 does not seem to be warranted in the case of this race unless other varieties, 

 and there are several, are also so baptized. In nearly all the lots are shells 

 close to pmnilum in general appearance. Pagoda may be considered a third 

 or fourth cousin to the southward and cariniferum a first or second cousin 

 to the north. 



Gyrotoma cariniferum Anthony 

 PI. I, figs. 14 and 15 



Gyrotoma carinifera Anth., Proc. Acad. Nat. Sci., Phila., XII, Feb. i860, p. 66; 

 Binney, Check List, i860, No. 310; Brot, List, 1862, p. 27; Paetel, Cat., 1888, p. 361. 



Melatoma cariniferum Anth., Reeve, ISIonog. Melatoma, 1861, sp. 13. 



Schizostoma cariniferum Anth., Lewis, Amer. Journ. Conchol., V, 1869-70, p. 168; 

 Tryon, Monog. Strepom., 1873, p. 353 ; Lewis, Fauna of Ala., 1876, p. 22. 



Schisochihis Showalterii Lea, Proc. Acad. Nat. Sci., Phila.. XII, ]\Iarch, i860, p. 

 93. 



Schizostoma Showalterii Lea, Journ. Acad. Nat. Sci., Phila., Y, n. s., 1862, p. 

 246, pi. 35, fig. 4Q; Obs. Gen. Unio, IX, 1863, p. 68, pi. xxxv, fig. 4Q. 



Gyrotoma Showalterii Lea, Binney, Check List, i860, No. 334; Brot, List, 1862, 

 p. 28. 



Gyrotoma olivtda excisa (Lea), Hannibal, Proc. Malacol. Soc, X, 1912, p. 181. 



