ORCULA. 5 



European Species (exclusive of Caucasus region). 



Lip more or less expanded, not reflected ; shell riinate 



and perforate (2) 

 Lip reflected; shell rimate, imperforate (7) 



A white palatal callus a short distance within the outer 

 lip, with or without an entering lower-palatal fold. 



2 ^ 0. gularis, no. 2 

 Inner margin of lip calloused or not; no palatal fold 



(3) 



' Parietal and columellar lamella? very much enlarged 

 within the last whorl, and emerging to edge of 



3 ^ peristome (4) 

 Parietal and columellar lamellae only moderately or not 



enlarged within last whorl (5) 



Shell having irregularly-spaced epidermal riblets ; about 



6.5 x 3.5 mm. 0. jetschini, no. 5 



Finely striate ; 5 to 6 x 2.8 mm. 0. conica, no. 3 



With fine, sharp, largely epidermal striae; thin, ovate; 

 aperture indistinctly triangular. 0. schmidti, no. 4 



Striate, without epidermal threads; aperture truncate- 

 oval, broadly rounded basally (6) 



Parietal and columellar lamellae penetrating inward to 

 or beyond the ventral side. 



0. dolium and varieties, no. 1 

 Lamellae much shorter; loess of Germany and Austria. 



0. d. plagiostoma, no. le 



Parietal lamella low and short, no columellar lamellae 

 visible ; 6.5 x 3 mm., 9-10 whorls. 0. bidgarica, no. 8 

 Parietal lamella entering deeply (8) 



Having spaced epidermal riblets when well preserved; 



parietal lamella not much enlarged within. 



0. doliolum, no. 6 

 Finely striatulate ; parietal lamella high and flaring 



outward within ; Greece. 0. s. grcocus, no. 12e 



8 \ 



