HELICELLA. 261 



H. couopsis Mor., iv, 22. H. mogadorensis Bgt., iv, 22. 



H. turcica Chemn., iv. 22. H. cyelostremoides Sby., iv, 256. 



cratera Schum. H. mograbina Mor., iv, 22. 



v. tetragona Mor., iv, 21. H. darolli (Let.) Bgt. 

 H. degenerans Mouss., iv, 22. v. djarica Bgt. 



/. validior Mouss. H. tunetana Pfr., iv, 21. 



Section Obelus Hartmann. 



Obelus HARTM., Erd- und Siisswasser-Gast. Schweiz, p. 158, type 

 O.preauxii. Xeroptyca MONTS., Moll. Terr. Is. adi. alia Sicil., 

 1892, p. 25, type H. " ptycodia "=ptychodia. 



Shell trochiform, with narrow umbilicus, acutely keeled and serrate 

 periphery (at least when young), with usually a secondary keel or 

 series of tubercles midway between periphery and suture ; solid, 

 whitish and earthy. Aperture basal, angular-oval, the lip simple 

 but slightly dilated at columella. Type H. despreauxii. 



Genital system (pi. 69, fig. 12, H. tuberculosa, typical) ; penis 

 having a subterminal elongated appendix; other organs as in Hel- 

 icella ericetorum, but dart sacks small. 



Distribution, Canary Is., eastward to Syria. A very natural 

 group, consisting of one series of species in Morocco and the Canary 

 Is. and another in Lybia to Palestine. Monterosato's name Xero- 

 ptyca belongs to the latter, but it seems unnecessary to make any 

 separation, and the term is etymologically bad. 



H. tuberculosa Conr., iv, 25 ; H. pumilio Pfr., iv, 27. 



[viii, 184. v. cyclodon W. & B., iv, 26. 



v. serrulata Bk., iv, 25. H. despreauxii Orb., iv, 25. 



H. philammia Bgt., viii, 185. preauxii Hartm. 



H. ptychodia Bgt., viii, 184. v. immodica Mouss. 



H. agenora West. H. moderata Mouss., iv, 26. 



H. berenice Kob., viii, 185. H. mirandse Lwe., iv, 2b'. 



H. lybica Pons., viii, 185. nodosostriata Mouss. 

 H. hesperidum Mor., iv, 26. 



Section Trochula Schliiter, 1838. 



Turricula BECK, Index Moll. 1837, p. 10, not Turricula Schum. 

 Essai, 1817, p. 217 (Pleurotomidce*). ? Oxynota HARTM., Erd- und 

 Siisswasser-Gast. Schweiz, 1842, p. 159, a nude name ; no species 

 mentioned. Crenea ALBERS, Die Hel. 1850, p. 77, in part, not 



