ORCULA. 125 



shells. The diam. is from 3 to 3.4 mm., length 6.8 to 8 mm. ; 

 some specimens occur above and below these dimensions. 



Orcula dolium infima St. Zim. [1. c. p. 14). Text-fig. 7, 



The largest of the species, up to length 9.1 diam. 4.1 mm., 

 with 9 to 10y2 whorls. Southern and eastern parts of the 

 Wiener Wald. It is very similar to the Carpathian (Bad 

 Trencsin-Teplitz) 0. d. titan Brancsik [vol. 27, p. 9]. 



Orcula dolium edita St. Zim. (l. c. p. 17). Text-fig. 8. 



Smaller, more cylindric than the typical form, diam. be- 

 tween 2.8 and 3 mm., length 6.7 to 7.3 mm. Palatal callus 

 and generally the peristome strongly developed. TJie upper 

 colmnelUir lamella is always weaker than the lower, sometimes 

 almost obsolete. This is the form of the middle heights of the 

 subalpine region to the limit of trees. The most characteristic 

 state of this morph is from the southern slopes of the Schnee- 

 berg massif ; also found in some heights of the northern Tirol 

 and Bavarian Alps, and in some places far down in the valleys. 

 0. d. uniplicata Pot. and Mich, apparently belongs in the 

 formenkreis of this morph, but no recent author has seen the 

 type. 0. d. plagiostoma Sandb. (Man. Conch, vol. 27, p. 11) 

 is also to be considered in this connection. ' ' I would confirm 

 that the plagiostoma of the Danube valley, which I know from 

 the loess at Passau, from Pielachberg at Melk, in the "Wachau, 

 and from Nussdorf and Heiligenstadt near Vienna (fig. 9), 

 agree in measurement, external shape and apertural characters 

 with the forms which live today in heights between 1000 

 and 1600 meters in the Niederosterreichisch-Steirischen 

 Kalkalpen." 



Orcula dolium oreina "A. J. Wagn." St. Zim. {I. c, p. 20). 

 Text-fig. 10. 



The shells are still smaller throughout than the morph edita. 

 The average dimensions are : diam. 2.6 to 2.8 mm., length 6.2 

 to 6.7 mm. ; whorls 8 to 9. They are thick-shelled and strongly 

 rib-striate ; the aperture is small and the palatal callus gener- 

 ally stronger than in edita. The reduction of the columellar 



