182 PLEURODISCIDAE. 



It is flatter, the lower side especially flattened, the umbilicus 

 is wider, the basal margin nearly straight ; the whorls increase 

 more rapidly than in the type, etc. I have not seen this form, 

 which from the above account seems to me except in size to 

 have more the characters of erdeli than of sudensis. 



Genus PYRAMIDULA Fitz. 



Pyramidula Fitzinger, 1833, Syst. Verzeich. Oesterreich 

 Weichthiere p. 95, for Helix rupestris Drap. 



For anatomy see : Soos, 1917, Ann. Mus. Nat. Hungarici vol. 

 16, pp. 114, 160, f. 88, 89.— Hesse, 1918, Nachrbl. D. Malac. 

 Ges. vol. 50, p. 110.— Watson, 1920, Proc. Malac. Soc. Lond. 

 vol. 14, pp. 6-30, f. 4a, pi. 2, f. 1, 3, 4. 



Shell small (diam. between 2 and 4 mm.), turbinate or de- 

 pressed with conic spire, of 4 to 5 strongly convex tubular 

 whorls and moderate or wide umbilicus; aperture toothless; 

 peristome simple, the columellar margin somewhat expanded. 



Jaw very thin, delicately striate. Radula with centrals 

 about as wide as the laterals, tricuspid with very small 

 ectocones (Watson), or unicuspid (Soos, Wiegmann) ; laterals 

 bicuspid; marginals wide, pectinate, with numerous narrow 

 cusps, no entocones. 



Reproduction ovo-viviparous ; penis enlarged distally (see 

 below), the penial retractor inserted on the vas deferens 

 (epiphallus ?) ; prostate gland of few tubules, posterior; 

 spermathecal duct rather short; neck of uterus and vagina 

 about equal in length (PL 29, fig. 2, P. rupestris, after Watson) . 



This genus inhabits the southern part of the Palaearctic 

 Region from Spain to Japan. Only a few species are recog- 

 nized. Possibly a few others included by Pfeiffer (Nomencl. 

 Hel. Viv.) in Patulastra may turn out to be Pyramidulae, 

 but most of the minute ones seem to belong to Punctum. The 

 type of Patulastra is Helix pygmaea Drap., designated by 

 Kobelt, 1880. 



The several accounts of the anatomy of P. rupestris differ 

 somewhat, so that Watson intimates that different species are 

 involved. Fritz Wiegmann, quoted by Hesse, states that the 

 penis was undeveloped in his specimens, its Anlage having a 



