TORNATELLIDES. 195 



f l . Columella with one or two rather 

 weak folds or lamellae in the adult 

 stage (two in the young). 



/. Columella with two lamella? 



(the upper stronger) , or with 



only an upper lamella or fold. 



Group of T. euryomphala, p. 230. 



f 1 . Columella with the lower 



lamella only. 



T. oncospira, no. 19. 

 <~. Columella with two rather strong, 

 oblique lamellae in both young and 

 adult. 



Group of T. thaanumi, p. 215. 

 Group of T. euryomphala, 



species nos. 39, 46, 47. 

 d 1 . Whorls flat ; the base tapering. 



Group of T. cyphostyla, p. 217. 



6 1 . Parietal lamella irregularly eroded; columella un- 

 armed. T. irregularis, no. 38. 

 & y . Parietal lamella regularly serrate or bearing a scythe- 

 like process. Group of T. terebra, p. 243. 



Group of T. simple. i . 



Tornatellides with rather few (4% to 6), more or less con- 

 vex whorls. Columella unarmed in adults (except in on- 

 cospira, which has a deeply seated lower columellar fold) . In 

 immature specimens only the lower columellar lamella or fold 

 is developed as such, when the upper fold is present it is rep- 

 resented by an oblique swelling. In some species there seem 

 to be no columellar lamellae at any stage. The parietal lamella 

 of immature specimens is usually much stronger than that of 

 adults, but sometimes it is only slightly so. 



1. Species of Formosa and the Japanese Islands. 

 It should be mentioned that G. Nevill reports an undeter- 

 mined species of " Tornatellina" from Shanghai the only 

 record we have for a member of this family on the mainland 

 of Asia. 



