180 PLEURODISCIDAE. 



Helix halmei Potiez et Michaud, 1838, Galerie Moll, de 

 Douai, I, p. 120. Paulucci, 1879, Journ. de Conch, vol. 27, 

 p. 7. Westerlund, 1889, Fauna Pal. Reg. Binnenconch, 

 Helix p. 13. — Helix flavida Zgl. Rossmaessler, 1839, Iconogr. 

 vol. 2, p. 13, f. 610.— Pfeiffer, Mon. Ilel. Viv. vol. 1, p. 144.— 

 Helix flavescens Parreyss in coll., Rossmaessler, 1839, I. c, 

 as syn. of H. flavida. — Helix teresae Benoit, 1845, Ricerche 

 Malacologiche, p. 9, pi. 2, f. 5 a, h. (Palermo, Cephalu, 

 Siracusa etc.). 



Rossmaessler 's good figures were copied by Tryon in M. C. 

 vol. 3, pi. 6, figs. 48-50. Potiez and Michaud 's description 

 and dimensions (7-8x12-14 mm.) were so ambiguous that 

 though often discussed, no one recognized that the well-known 

 H. flavida was intended until Mme. Paulucci examined the 

 types in 1879. It was a pity to displace the well-defined 

 name flavida. 



Pleurodiscus erdeli (Roth). PL 25, fig. 16. 



Shell widely umbilicate, depressed, elegantly costulate, 

 pellucid, buff-corneous, paler beneath. Whorls rounded. 

 Aperture transversely lunate-ovate ; peristome straight, simple, 

 flexuous. Alt. 21/^, diam. 3% lines; 5 whorls. Differs from 

 H. ruderata Stud, by the size, the narrower umbilicus and 

 more depressed aperture (Roth). 



Rhodes, type loc. Roth; Syria at Beirut; Palestine; Asia 

 Minor; Constantinople. 



Helix erdelii Roth, 1839, Moll. Species in Itinere per 

 Orientem facto, etc., p. 16, pi. 1, f. 4, 5, 20. — Pfeiffer, 

 Monogr. I, p. 105. 



I have not seen specimens from Rhodes. A Beirut example 

 figured measures height 6.1 mm., diam. 10.7 mm. ; barely 6 

 whorls. It is cinnamon-buff, the umbilicus noticeably wider 

 than in P. halmei, more perspective. In the aperture a white 

 callus lining is seen, stronger than in P. halmei, of which some 

 authors consider erdeli a variety. It was named for Dr. M. 

 Erdl, Roth's travelling companion in the Orient. 



It has been recorded from Malta by Issel (1868, Bull. Malac. 

 Ital. I, p. 5, the specimens identified by Bourguignat). 



