246 The Molluscan Family Planorbidae 



PLATE 5 



Pingiella and Polypylis 



1,5. Pingiella peipinensis (Ping and Yen), new genus. Peiping, China. 



1. Region of the pseudobranch. 



5. Spermatheca of different shape. 



2-4,6,7. Polypylis hemisphaerula (Benson). Peiping, China; from Fan Memorial 

 Institute. 



2. Outline of albumen gland. 



3. Region of the pseudobranch. 



4. Section through prostate and ducts. 



6. Distal end of verge showing outlet of canal at the side. 



7. Entire genitalia dissected and organs separated. 



Line near figure indicates 1 mm. in length. Figure 6 is greatly enlarged. 



