260 PERUSSACIA, SECTION PEGEA. 



irregularly increasing, the upper flat, the rest a little convex, 

 the first narrow and small, the sixth large, last very large, sepa- 

 rated by a paler, superficial, duplicated suture; last whorl 

 large, two-fifths the total length, convex, shortly and suddenly 

 deflexed at the upper insertion of the lip. Aperture narrow, 

 elongate, angular above, a little convex outwardly, angular 

 below at the base of the columella, with a thick, produced 

 parietal lamella within. Columella straight, thick, lamelliferous, 

 the lamella superior, deeply placed. Peristome unexpanded, 

 whitish, obtuse, a little thickened within; outer margin lightly 

 arched forward, margins joined by a strong callus. Length 18, 

 diam. 6 mm. (Bgt.}. 



Algeria: Summit of Mt. Guerium, between Constantine and 

 Tebessa; Mt. Maadid, between Hodnaand Medjana (Letourneux). 



F. letourneuxi BGT. , Species novissima 1 Moll, in Eur. syst. 

 detects, p. 32 (1876). Cionella letourneuxi Bgt., WESTERLUND, 

 Fauna, iii, p. 164. 



This species is the largest of its group. It is figured from a 

 specimen measuring, length 16.5, diam. 5.7, aperture 7.8 mm. 



Var. grossa ' Ancey ' Westerlund. Somewhat smaller, slen- 

 derer, less ventricose, thick-shelled; aperture smaller; columella 

 broad, callously thickened, toothless; parietal lamella callous, 

 generally hardly emerging. Length 15 to 16 mm. Algeria at 

 Ain M'lila (Wcsterl, Fauna, Supplement, p. 48, 1890). 



50. F. BERTHIERI Bourguignat. 



Shell oblong, very much attenuate at the summit, very glossy, 

 subpellucid, opaque and rather thick at the aperture, polished, 

 pale corneous or milky; spire moderately produced, almost 

 suddenly tapering, and at the summit more slender and sub- 

 acuminate, the apex rather obtuse. Whorls 7, the first 4 small, 

 a little convex and closely coiled, the fifth larger and more con- 

 vex, penult, and last large. Suture linear, rapidly descending 

 between the fifth and penult, whorls; last whorl but slightly 

 convex at the beginning, becoming more convex at the aperture. 

 Aperture vertical, piriform-elongate, very angular above, with 

 a parietal lamella. Columella straight, acuminate, rather 

 strongly toothed inwardly above. Peristome obtuse, thick, 



