HELICELLA. 265 



cent, the surface finely malleated, shining ; last whorl wide, slightly 

 descending. Aperture wide-lunar, but little oblique ; lip acute, 

 slightly expanded below, strengthened within by a distinct submar- 

 ginal rib. Type H. carthusiana Mull., pi. 68, figs. 25, 26. 



Jaw with numerous flat, close ribs. Marginal teeth with an-ab- 

 normally large number of denticles, at least in some species. Penis 

 short and swollen, passing into an epiphallus which ends in a short 

 flagellum and the vas deferens ; no retractor muscle. Mucus glands 

 inserted high on vagina, at root of spermatheca duct, and consisting 

 of three pairs of tubes. Far below them is a long blind sack with 

 plicate internal walls, but containing no dart, evidently a degenerate 

 dart sack. Spermatheca irregular-oblong, its duct long and branch- 

 less. Right eye retractor not passing between branches of genitalia 

 (pi. 69, fig. 22, H. carthusiana. PI. 69, fig. 16, H. syriaca. PI. 69, 

 fig. 14, H. cantiand). The arrangement and number of mucus 

 glands varies in the different species. 



Distribution, middle and southern Europe and Asia Minor. 



The group is well distinguished by the whitish but still somewhat 

 translucent, finely malleated shell, with conspicuous lip-rib, as well 

 as by the lack of penis retractor muscle (cf. Cepolis) and the lack 

 of a dart in the lengthened but evidently degenerate dart sack. 



Risso's genus Theba contained ten species of several groups, but 

 after eliminating the first three and last two, which were removed 

 by subsequent authors to other groups, Euparypha, Cochlicella, etc., 

 we have left five forms of the If. carthusiana type. Westerlund 

 lias made these the basis of Theba; and it seems better to follow 

 his example rather than to legislate the group completely out of ex- 

 istence as we would be compelled to do were we to adopt Kobelt's 

 name Carthusiana, proposed in 1871. The latter name is, more- 

 over, objectionable from being the duplication of a specific name, al- 

 though this alone would not bar its acceptance. Gray's Zenobia is 

 founded upon a species of this group, but is preoccupied. It has 

 been used hitherto in a totally incorrect manner by European 

 "writers, evidently from failure to consult the original paper in 

 which it was proposed. Westerlund's group Euomphalia is founded 

 on H. strigella and its allies, which are anatomically like Theba. 

 H. alphabucelliana Paul., iii, 204. dacampi Villa. 

 H. anconse Iss., iii, 192. /. carfaniensis Stef. 



oliviaria, Iss., olim. v. marchetti Stef. 



rubella Risso. v. simplicita Parr., iii, 194. 



UNIVEBSIIY 



