258 HELICELLA. 



H. monilifera W. & B., iv, 20. H. cjementitia Sh., iv, 20. 



H. lancerottensis W. & B., iii, H. tumulorum W. &B., iv, 19. 



v. webbii Lwe. [237. ? atomata Mke., iv, 21. 



v. bertheloti Lwe. H. oleacea. Sh., iv, 20. 



v. adoptata Mouss. v. deusta Lwe. 



H. persimilis Shutt., iv, 19. H. woodwardia Tarn., iv, 20. 



v. prseposita Mss. H. watsoniana Woll., iv, 21. 



v. devia Mouss., iv, 20. H. lemniscata W. & B., iv, 21. 



H. phalerata W. & B., iv, 19. H. orbignyi W. & B., iii, 237. 



rosetti W. & B. orotavana Tarnier. 



nivariensis Sh., Rve. v. mitigata Mouss. 



H. umbiculaSh., iv, 21. v. calcarea Mouss. 



roseti Pfr. not W. & B. H. phryganophila Mab. 



phalerata Pfr. not W. & B. H. dendrophila Mab., iii, 237. 



H. aglaonieta Mab., iii, 237. 



Section Jacosta Gray, 1821. 



Jacosta GRAY, London Med. Repos., xv, March 1, 1821, p. 236, 

 only species mentioned H. Jacosta albella ~Drap.= explanata Miill. 

 Numidia ISSEL, Ann. Mus. Civ. Genov. xxii, 1885, p. 8, 9, type H. 

 idia Bgt. Xerofalsa MONTS., Moll. Terrest. delle Isole adiacenti 

 alia Sicilia, 1892, p. 21 (for H. idia, eniea, zougitana). Xerosecta 

 MONTS., L c. (for H. explanata). Xeroplana MONTS., 1. c. (for H. 

 doumeti, depressula). Xerotropis MONTS., t. c., p. 23 (for gargottce, 

 jolyi. prietoi, ledereri, milaschewischi, spratti). Xeroamanda MONTS., 

 t. c., p. 22 (for amanda, ustieensis). Xeromoesta MONTS., L c. (for 

 moesta, kaby liana, dormiens, dohrni). Xerocodia MONTS., t. c. p. 23 

 (for montserratica, penchinati, barneana). Xeroplexa MONTS. I. c. 

 (for setabulensis, nyelli, coronadoi). Tropidocochlis LOCARD, Ex- 

 change ix, p. 97, 1893, type H. explanata. 



Shell umbilicated, the whorls flattened above, acutely keeled at 

 periphery, and convex beneath; surface costulate, striate or smooth- 

 ish ; solid and earthy, whitish with or without bands, the apex black 

 or light. Aperture angled, the lip rather blunt, not expanded. Type 

 H. explanata Miill., pi. 68, figs. 23, 24. 



Jaw arcuate and ribbed. Genital system (pi. 69, fig. 15, H. ex- 

 planata) with the flagellum rather longer than usual in the genus ; 

 dart sack slightly bilobed at apex and containing two darts ; mucus 

 glands numerous. 



