LAURIA, SUBGENUS LEIOSTYLA. 



69 



r Outer lip strongly bent in below the sinulus; peristome 

 thick, crenulate ; 3.5 to 4 mm. long. 



<H 



L. zonata, no. 19 

 ^ Outer lip not bent in below the sinulus (8) 



Length less than 3 mm. L. tenuimarginata, no. 17 



Length more than 4 mm. (9) 



Small basal and upper-palatal folds present; peristome 

 thick, crenulate ; 4.2 to 5 mm. long. 



L. superstracta, no. 18 

 A small basal fold but no entering upper-palatal; peri- 

 stome simple, whitish ; 5.25 mm. long. 



L. s. lederi, no. 18a 



No basal or entering upper-palatal folds; 4.6 to 5 mm. 



long. L. s. unibasalis, no. 186 



, Perforate and rimate, the base rounded; 2 lamella? on 

 I columella; lip crenulate (11) 



10 I Deeply umbilicate, the base keeled ; 1 lamella on colu- 

 l mella. L. pontica, no. 21 



Beautifully, sharply costulate ; 3.5 to 4 mm. long. 



L. pulchra, no. 20 

 | Finely rib-striate ; glossy brown ; 4 to 4.5 mm. long. 

 I L. p. nit ens, no. 20a 



Species of the Atlantic Islands. 



Madeira group (13) 

 2 -> Azores (38) 



Canary Islands (36) 



(Madeiran Species.) 



' Parietal lamella higher than the angular, which is not 

 connected with the lip insertion; teeth large, but 

 the palatals and basal deeply immersed; lip-tooth 

 strong, nearly closing the sinulus; shell small, 

 ribbed, the diam. % to % of the length of about 2 

 mm. (section Wollastonula). L. gibba, no. 46 



Parietal lamella not higher than the angular, often dis- 

 tinctly lower (14) 



