NERITID.E. / 



Neritoglobus, Kobelt. 1871, Elea, Ziegler. 1833, and Neritoconus, 

 Kobelt. 1871, are synonyms, N. fluviatilis, Linn. 



Kobelt separates the species into two subsections, according to the 

 globose or conical shape of the shell, but the latter form represents 

 an abnormal growth, including specimens of species undoubtedly 

 belonging normally to the former. 



Section Neritodonta, Brusina. 1884. 



Columella thickened, callous, columellar margin subdenticulated ; 

 parietal apophysis projecting. N. Lukovici, Brusina. Tertiary 

 of Dalmatia. The genera (!) Tripaloia, Letourn., and . Calvertia, 

 Saint-Slmonia, Petrettinia and Burgersteinia, Bourg., are identical. 



Section Neritilia, Martens. 1879. 



Columella smooth ; operculum with a single erect spatulate pro- 

 cess. N. succiNEA, Recluz. Guadeloupe, W. I. 

 Section Smaragdia, Issel. 1869. 



Eyes sessile at the base of the tentacles. Shell greenish, ob- 

 liquely oval, with short spire ; columellar area callous, the margin 

 finely denticulate. N. viridis, Linn. Marine. 



West Indies, Mediterranean, Pacifie. 



Gaillardotia, Bourg. 1876, is a synonym. 



Section StAnleya, Bourg. 1885. 



Brilliantly polished, transparent, spirally sulcate, imperforate, 

 with large parietal callus, 3 sp. Lake Tanganyika. N. neki- 

 TOiDES, Smith. 



Section Clypeolum, Recluz. 1850. 



Shell globular, oval or conic, covered by a corneous epidermis, 

 columellar margin not dentate, outer lip prolonged upward on the 

 spire in a tongue-like manner. Operculum colored, with well de- 

 veloped apophyses, the claviform apophysis grooved. Fluviatile. 

 Indo-Pacijic. N. pulligera, Linn. 



Section Neritona, Martens. 1869. 



Oval globular, with very short spire ; peritreme widely developed, 

 subcontinuous, columellar margin not denticulate. Operculum with 

 the apical process depressed, flattened, lobate at the tip. Fluviatile. 

 N. labiosa, Sowb. 



Subgenus Clithon, Montfort. 1810. 



Shell coronated with tubercles, or short or long spines (sometimes 

 unarmed), and covered by a corneous epidermis ; margin of colum 



