TORN ATELL ARIA. 255 



diam. of base. 



T. occidentalis, no. 3. 

 I' 1 . Two columellar lamella; 

 emerging. 



g. Umbilicus about one- 

 sixth the diam. of base. 

 T. adelince, no. 2. 

 y 1 . Umbilicus one-eighth 

 the diameter or less. 



T. newcombi, no. 4. 



e 1 . Base tapering, outlines of spire 

 slightly concave. 



T. anceyana, no. 9. 

 & 1 . Adult shells with less than 7 convex whorls. 



T. baldwinia-na , no. 16. 



a 1 . In adult specimens the diameter is 60% or more of the 

 length. 



6. Parietal lamella 0.2 mm. in height or more. 



c. Umbilicus large, about one-sixth the diam. of 

 base. T. adelina: var., no. 2. 



c 1 . Umbilicus minute. 



d. Only the upper columellar lamella emerg- 

 ing, shell obese. T. abbreviata, no. 13. 

 d 1 . Two columellar lamellae emerging. 

 e. Shell larger, over 4' mm. long. 



T. a. hawaiiensis, no. 13o. 

 e 1 . Shell smaller, less than 3.5 mm. 

 long. 



/. Parietal lamella entire an- 

 teriorly. T. stokesi, no. 5. 

 /'. Parietal lamella excised an- 

 teriorly. T. sharpi, no. 15. 

 ft 1 . Parietal lamella less than 0.2 mm. in height. 



c. Adult shells with more than 7 almost flat 



whorls. Shells not glossy. T. lil<r, no. 1. 



c 1 . Adult shells with less than 7 slightly convex 



whorls. Shells glossy. T. smithi, no. 14. 



