FERUSSACIA, SECTION PEGEA. 259 



"So similar to F. graeilenta that Westerlund ranks it as a 

 subspecies of that. The chief difference is in its more slender, 

 pronouncedly fusiform shape, smaller size, the reduced or 

 wholly wanting parietal lamella and the somewhat more 

 strongly forwardly-arched outer lip" (Kobelt). 



48. F. TERVERI Bourguignat. PL 44, fig. 19. 



Shell rather small, cylindric-fusiform, very glossy, pellucid, 

 polished, pale corneous or corneous-fulvous ; spire a little 

 lengthened, gradually acuminate-tapering; apex paler, a little 

 obtuse. Whorls 6, a little convex, the first regularly increas- 

 ing, the rest more rapidly, separated by a rather impressed 

 paler, duplicated suture; last whorl convex, nearly half the 

 total length. Aperture piriform-oblong; having a minute, very 

 deeply immersed, hardly visible parietal lamella. Columella 

 simple, straight, sometimes lamellar within and having a cal- 

 losity above. Peristome unexpanded, acute, the outer margin 

 arcuate especially below; margins joined by a very thin callus. 

 Length 7 to 8, diam. 2.5 to 3, aperture 3.5 mm. (BgL). 



Algeria: very common around Algiers; Blidah, Bougie, etc. 



Achatina folliculus TERVER, Catal. Moll. Afric. p. 31, pi. 4, 

 f. 16, 17 (1839). F. terveri BGT., Amen. Malac. i, p. 208 

 (1856); Malac. de 1'Algerie ii, p. 64, pi. 5, f. 1-3. KOBELT, 

 Iconogr. vii, p. 31, pi. 187, f. 1188. 



Smaller than F. gracilenta, less lanceolate, the last whorl 

 generally larger than the spire, the aperture less dilated below, 

 the parietal lamella smaller, very deeply immersed and gen- 

 erally not visible. 



Group of F. letourneuxi. 



Remarkable for the brilliant gloss of the shell, the abruptly 

 attenuate spire and the very irregular increase of the whorls. 



F. aristidis Bgt. is an undescribed species of this group from 

 Algeria. See Prodr. Mai. Tunisie, p. 116, footnote 3. 



49. F. LETOURNEUXI Bourguignat. PI. 44, fig. 23. 



Shell large, long-oblong or tumid-subfusiform, glossy, pellu- 

 cid, smooth, corneous. Spire long, rather shortly acuminate- 

 tapering at the summit, the apex paler, minute. Whorls 8 



