GEOMITRA. 239 



believing it an ancient inhabitant of the Madeira group, and its 

 peculiarities have probably been developed upon that soil, for neither 

 in the fossil series of Europe or the recent fauna of Eur-Africa or 

 the other Atlantic islands are there known formi which may be re- 

 ferred to the Madeira genus. It is therefore much more restricted 

 that the Leptaxis group. In this connection conf. WATSON, The 

 Journal of Conchology. vii, p. 1, 1892. 



A large number of subgenera or sections have been founded for 

 the Madeira Helices, which is not surprising when we consider the 

 astonishing amount of modification of the numerous minor groups, 

 altogether unparalled in any other tract of like extent in the world. 

 Most of the following sectional groups have already been associated 

 by Martens, Pfeiffer and others ; but Plebecula, Helicomela and His- 

 pidella are now added to the group for the first time. 



The name Ochthephila being preoccupied, I have been obliged to 

 substitute Swainson's term Geomitra. This has priority over Heteros- 

 toma Hartmann, as well as over the entire series of names proposed 

 by Lowe. 





Subgenus PLEBECULA Lowe, 1852. 



Plebecula LWE.. Ann. Mag. Nat. Hist. (2), ix, p. 114, Feb., 1852, 

 for giramica, vulgata, canicalensis Lwe. ; P. Z. S., 1854, p. 172, type 

 H. vulgata Live. Helicomela LWE., P. Z. S., 1854, p. 172, type H. 

 pundulata Sowb. 



Shell globose-depressed with conic spire, or subglobular, umbili- 

 cate or imperforate, solid, above rather rudely striated, granose or 

 hirsute ; unicolored, or 3-banded above on a brown ground, the base 

 paler and uniform. Whorls 5-6, separated by deep sutures. Aper- 

 ture but little oblique, subcircular ; lip hardly expanded, sharp or 

 thickened within ; columella reflexed. Type G. nitidiuscula Sowb. 

 (See pi. 43, fig. 26, G.punctulata Sowb.). 



(Shell subglobular, imperforate ; Helicomela). 



G. punctulata Sowb.,iv, 187. G. bowdichiana Fer., iv, 187. 

 v. avellana Lwe., iv, 187. vargasiana Pfr. 



(Shell depressed-globose with conic spire, umbilicate ; Plebecula). 



