240 The Molluscan Family Planorbidae 



PLATE 2 



Segmentina and Hippeutis 



1-6. Segmentina nitida (Miiller). From swamps on a meadow near Warsaw, Poland; 

 from A. Jankowski. 



1. Cross section of pilaster to which appendage is attached. 



2. Vertical section of preputium showing position of gland-like appendage. 



3. Upper view of cup of gland or appendage. 



4. Vertical section of gland or appendage. 



5. End of verge showing position of vergic appendage. 



6. End of verge showing vergic appendage and outlet of sperm canal. 



7-15. Hippeutis complanatus (Linn.). From pool in meadow in Jabtonna, 16 km. north 

 of Warsaw, Poland; collected by A. Jankowski. 



7. Two diverticula of ovotestis. 



8. Cross section of prostate showing two canals, one for prostate (PD) and one 



for sperm duct (SPD). 



9. Gland or appendage in preputium. 



10. Outline of albumen gland (from above). 



11. Upper part of vergic sac showing two flagella and the vas deferens. 



12. Vertical section of penial complex showing relationship of verge, gland, or 



appendage, and flagella. 



13. Head of animal showing form of pseudobranch and pneumostome. 



14. Penial complex from the outside. 



15. General dissection of genitalia omitting the penial complex. 



Line near figure indicates 1 mm. in length. Line at left of fig. 12 also indi- 

 cates .size of figs. 3, 4, 5, 8, and 9. Figures 6 and 11 are greatly 

 enlarged. Figure 14 has same magnification as fig. 15. 



