PLEUKODISCIDAB. 183 



length of 0.4 mm., consisting of a somewhat curved, club- 

 shaped, blunt body, which receives the vas deferens at about 

 the distal third, the penial retractor inserted on the vas 

 deferens. Soos described the penis as remarkably small, fusi- 

 form, distally recurved upon itself, the two parts lying close 

 together; tapering suddenly into the very long, thread-like 

 vas deferens ; the weak retractor inserted on the thickest part 

 of the penis. Watson, whose figure is copied in PI. 29, fig. 2, 

 says "penial appendix much reduced, being represented by a 

 mere knob, without muscular attachment". It appears to me 

 very doubtful whether the distal enlargement of the penis is 

 correctly considered to be homologous with the appendix of 

 Vallonia, etc.; Soos' figure does not show it, though he men- 

 tions that the transition from penis to vas deferens is abrupt. 

 The male organs seem to be very similar to those of some 

 Vertigininae, such as Columella as figured by Steenberg ( 1925, 

 p. 100). 



According to Moquin-Tandon the uterus contains 3 to 7 

 embryos; Watson's figure shows 2 or 3. Both Wiegmann and 

 Soos report not more than one in the specimens they opened. 



Wenz (1923, Fossilium Catalogus, p. 1062) recognizes two 

 Tertiary species: 



P. ANTONiNi (Michaud, 1862), Pliocene, Hauterive (Drome). 



P. SUBTERES (Clessin, 1877), Upper Mioc, Undorf bei 

 Eegensberg. 



Helix (Patula) recurrecta Oppenheim, 1890, from the 

 Eocene of Monte Altissimo, Prov. Vicenza, perhaps belongs 

 here ; see also p. 12. 



Pyramidula rupestris (Drap.). PL 25, figs. 9, 9a, 9&. 



The low-conic shell is openly umbilicate (the umbilicus con- 

 tained about five times in the diameter), hazel or russet, 

 glossy, finely, irregularly striate, the initial 1^^ whorls micro- 

 scopically granulose; composed of 4 strongly convex whorls, 

 which are flattened below the deeply impressed suture. The 

 aperture is basal, oval, the thin peristome expanded a little 

 at the columella. Parietal callus transparent, very short. 

 Height 1.8 mm., diam. 2.3 mm. 



