250 FERUSSACIA, SECTION PEGEA. 



the left than on the right side, rather slowly increasing to the 

 penult, whorl, then rapidly, parted by a whitish linear suture ; 

 the last whorl large, half the total length, quite convex. 

 Aperture vertical, irregularly oblong, within whitish, and 

 having a strong parietal lamella, Columella stout, short, 

 white, acuminate, within rather strongly denticulate above. 

 Peristome straight, acute, thickened with white within; outer 

 lip almost straightly descending, slightly retracted towards 

 the base, margins joined by a strong callus. Length 11, diam. 

 4, aperture 5.5 mm. (Bgt.) 



Tunis: environs of Bizerte; Djebel Recas. 



F. gibbosa BGT., Prodr. Malac. Tunisie p. 122. 



F. punica Bourguignat. Shell long-cylindric, above rather 

 abruptly tapering, below rather strongly convex and produced 

 to the right at the outer margin of the aperture, a little glossy, 

 subopaque, thick at the aperture and base, corneous, polished. 

 Spire long, cylindric, apex minute, but a little obtuse. Whorls 

 7, slightly convex, or rather, subplanulate ; rather rapidly and 

 regularly increasing, separated by a linear suture ; last whorl 

 quite convex on the right at the outer lip, very opaque and as 

 though projecting in a crest below at the columella. Aper- 

 ture subvertical, irregularly oblong, acute above, within whit- 

 ish, and with a strong parietal lamella, Columella straight, 

 strong, either acuminate or a little truncate at the base, with- 

 in denticulate above ; peristome whitish, unexpanded, obtuse, 

 slightly spreading below, thickened within; outer margin 

 nearly straight, receding at base ; margins joined by a strong 

 callus. Length 14, diam. 4, aperture 5 mm. (Bgt.}. 



Tunis: ruins of Utique and Carthage, Djebel Recas etc. 

 Algeria, around Constantine. 



F. punica BGT., Prodr. Malac. Tunisie p. 122, 1887. Ko- 

 belt's fig. 1193, copied in my pi. 43, fig. 8, represents this form. 



F. polyodon Letourneux et Bourguignat. Shell elongate, 

 slightly more convex on the left than on the right margin, 

 glossy, rather opaque, the last whorl more opaque, pale cor- 

 neous, finely striatulate but polished; spire produced, regu- 

 larly tapering, the apex minute, a little obtuse; whorls 7, a 

 little convex, regularly increasing, separated by a slightly im- 



