334 HELIX. 



Subgenus EREMINA Pfeiffer, 1855. 



Eremina PFR., Mai. BL, 1855, p. 139, sole species H. desertorum. 

 Eremophila KOBELT, Katalog Eur. Binnenconch., p. 19, 1871 ; 

 Iconographie iv, p. 13. Erinna MORCH., Journ. de Conch., 1865, 

 p. 387 (desertorum). Eremia Auct. Conf. JICKELI Moll. N.-O.- 

 Afrika's, pi. 1, f. 7-9 (dentition, jaws and darts) ; SCHUBERTH, 

 Archiv f. Naturg., 1892, pi. 5, f. 11, 12 (teeth and dart). SEMPER, 

 Reisen im Arch. Phil. Landmoll., pi. 14, fig. 14 (genitalia). 



Shell iraperforate or narrowly umbilicate, solid, chalky, with 

 rudely striate surface; white with reddish bands or suffused and 

 streaked with tawny. Whorls about 5, the last somewhat or not 

 descending. Aperture slightly oblique, wide lunate ; lip a little 

 expanded and blunt or greatly thickened, the columellar margin 

 reflexed, arcuate, not thickened by an internal plate of callus. Type 

 H. desertorum Forsk., pi. 44, figs. 12, 13 ; also fig. 14, var. ehrenbergi 

 Roth, (chilembia Bgt.) 



Jaw stout, arcuate, with blunt ends; having grouped near the 

 middle two to four strong ribs dentating both margins (pi. 67, fig. 

 9, H. desertorum ; fig. 8, H. desertella). Radula having basal plates 

 rather short; cusp attaining edge of basal plate, the side cusps ob- 

 solete; laterals bicuspid, with a small outer cusp. Marginals 

 having the larger cusp bifid, the ectocone also splitting on the outer 

 ones (pi. 67, fig. 10, H. desertorum). 



Genitalia: Spermatheca duct long (45 mill.) ivith no diverticulum. 

 Dart sack small, containing a two-bladed dart with serrate crown, 

 and a longitudinal rib or sometimes a blade on one or each side 

 (pi. 63, fig. 6, H. desertorum). Mucus glands 2, long pediceled, 

 branching into 5 to 6 fine tufted fingers. No flagellum on penis, the 

 retractor and vas deferens terminal (pi. 63, fig. 4, H. desertorum). 



The solid, cretaceous shell and lack of flagellum on the penis 

 ally this group to Euparypha; the long-stalked pair of digitate 

 mucus glands and the tendency to be five-banded are points of like- 

 ness to Tachea. The dart is slightly coronated at base, the head 

 long and two-bladed, but with side ribs which sometimes develop 

 into blades, and it, therefore, is mainly of the type common in Pen- 

 tata3nia. A diverticulum on spermatheca duct is wanting, but this 

 feature varies greatly even among closely allied species. 



The species are desert forms, inhabiting northeastern Africa. 



