PLATE II. 



(The specimens are figured natural size except when otherwise stated.) 



Figs. 1,2. Valvata Aeh'coidea Dall, magnified four diameters. The umbilicus 

 is partly hidden by a calcareous deposit ; p. 123. 



3. Lymncea petersiT)a\l; p. 66. 



4, 5. LymncEa anticostiana Dall; p. 79- 



6. Lymncea ? perpolita Dall ; p. 78. 



7. 9. Lymncea atkaensis Dall; p. 66. 



8. Lymnaa f perpolita Dall, magnified two diameters ; p. 78. 

 10, II. Planorbula christyi 'Dall, magnified two diameters; p. 99. 



(156) 



