1918.] N. Anxaxdale: Molluscs of the InU Lake. 161 



theohaUi) I have already referred as representing the ancestral type. I 

 have also referred to the fact that in it the generic characters are less 



Fig. 8. Diagram showing tlic relations of the different described species of Taia. 



marked than in the other species, the spiral ridges on its shell beina 

 less strongly developed and its columellar callus less expanded. 



