244 FERUSSACIA, SECTION PEGEA. 



unexpanded, subacute, a little thickened within and some- 

 what whitish ; outer margin regularly arcuate ; margins 

 joined by a thin callus. Length 13, diam. 4, aperture 5 nun. 

 (Bgt.) 



Tunis: debris of the Oued Sidi-Aich; Algeria: around 

 Calle and Bone. 



F. littoralis BGT., Prodr. Malac. Tunisie p. 119, 1887. 

 'Remarkable for the regularity of its spiral increase and 

 the convexity of the whorls. ' ' 



28. F. EULISSA 'Let.' Bgt. 



Shell oblong-elongate, rather swollen, obese, very obtuse at 

 the summit, glossy, fragile, smooth, pale corneous. Spire ob- 

 long, slightly acuminate but obtuse; apex obtuse, white. 

 Whorls 6, a little convex, the upper slowly, the rest rapidly 

 increasing, separated by a paler superficial and duplicated 

 suture, the last whorl two-fifths the total length, a little con- 

 vex, slightly descending to the lip-insertion. Aperture rather 

 lunate, oblong-piriform, acutely angular above, convex below, 

 with a deeply immersed very minute median parietal lam- 

 ella. Columella short, straight, lamellar. Peristome acute, 

 unexpanded, whitish, slightly thickened within. Outer mar- 

 gin arched forward, the margins joined by a very thin callus. 

 Length 10, diam. 3 mm. (Bgt.). 



Algeria: Djebel-Thaya, Hammam-Meskhoutin and ravine 

 of the Rummel near Constantine ; Tunis : debris of the Oued 

 Sidi-Aich. 



F. eulissa Letourneux, in BOURGUIGNAT, Species Novissimae 

 molluscorum in Europaeo Syst. detect* p. 33 (1876) ; Prodr. 

 Malac. Tunisie p. 119. 



"Remarkable for its obtuse spire." 



Group of F. nympharum. 

 Shape somewhat Alexia-\\ke. 



29. F. NYMPHAJRUM Letourneux et Bourguignat. 



Shell long-oblong, moderately shining and pellucid, dark 

 corneous or somewhat olivaceous, paler at the summit and 



