PLATE II. 



Diagrammatic Enlargements of the Hinges of: 



1. Pisidium pulchellum. 



2. viucentianum. 



3. subtruncatura. 



4. henslowanum. 



5. supinum. 



6. parvulum. 



7. steenbuchii. 



8. lilljeborgii. 



9. Jiilcrnicitm. 



10. 



In tlie above Plate the white dots are placed opposite the 

 apices of the inner lateral teeth. 



