72 LAURIA, SUBGENUS LEIOSTYLA. 



( Lip-tooth defining the sinulus weak; shell long, cylin- 

 dric, the diam. much less than half the length; a 

 basal fold present (30) 



Lip-tooth moderately developed; shell cylindric, diam. 

 less than half the length ; no basal fold ; 3.7 x 1.5 

 mm. L. s. simulator, no. 33c 



Lip-tooth moderately or strongly developed; shell more 

 or less tapering upwards ; diam. equaling or exceed- 

 ing half the length (31) 



30 \ 



31 \ 



32 



33 < 



Finely striate on the spire ; supracolumellar lamella and 

 upper-palatal fold well developed. 



L. s. arborea, no. 33a 



Finely striate on the spire ; a rather weak supracolumel- 

 lar lamella and no distinct upper-palatal fold; 4.7 

 to 5x 1.5 mm. L. recta, no. 36 



More sharply striate throughout; no supracolumellar; 

 3.7 x 1.4 mm. L. r. macilenta, no. 36a 



' No supracolumellar lamella; callus connecting the an- 

 gular lamella and lip insertion irregular, inter- 

 rupted or tubercular. L. laurinea, no. 32 

 Supracolumellar lamella present; an even callus con- 

 necting the angular lamella and lip insertion. 



L. irrigua, no. 28 

 L. loweana, no. 29 



Parietal lamella small and short, not entering deeply; 



shell rather narrow, diam. less than half the length. 



L. laevigata, no. 35 

 Parietal lamella long, entering deeply ; shell wider, diam. 



half the length or more (33) 



Cylindric, the upper third convexly conic ; sharply stri- 

 ate ; lip-tooth below the sinulus well developed. 



L. concinna, no. 31 



Somewhat tapering from the last whorl; an inward 

 prominence below sinulus but not a definite tooth ; 

 striation weak (34) 



