OF PLANORBIS AT STEINHEIM. 109 



Formation h, Section 6. 



PI. triquetrus, line g, ligs. 17-23. 



PI. discoideus, Hue h, figs. 1-18, i 1-14, k 1-2. 



PI. diseoideus (rotundatus-like young), line h, figs. 19-23. 



PI. diseoideus (var. elatior Sand.), line i, figs. 15-17. 



PI. trochiformis, line k, figs. 3-11, 1 1-11. 



Pi! diseoideus, line m, figs. 3-4, 6-9. 

 PI- '£iSS,f line ra, figs. 1-2, 5. 



Formation i. Section 6. 



Formation k, Section 6. 



PL diseoideus, line n, figs. 1-7. 



PI. troehiformis, line n, figs. 8-12, o 15-18. 



PI. troehiformis (votundatus-llke young), line o, figs. 1-14, p 1-8. 



PI. tenuis, line p, figs. 9-13. 



Formation 1, Section 6. 



PI. minutus, line p, figs. 14-20. 

 PI- "^^ line q, fig. 1. 

 PI. denudatus, line q, figs. 2-4. 

 PI. tenuis, line q, figs. 5-11. 



P''- SteinheSnensis, "^^ 'il ^g- 1-^- 



PI. diseoideus, line q, figs. 13-16. 



-PZ- 'ifcfS? line q, figs. 17-18, r 1-4. 



PI. troehiformis, line r, figs. 5-10, s 1-8. 



PI. troehiformis {xzx. pyrguliformis Sand.), line s, figs. 9-12. 



Plate HI. 



Magnified 2 diameters. 



List of Species. 



PI. diseoideus, line c, figs. 17-19, d 1-11, e 1-12, f 1-14, g 1-9, h 1-10, i 5-9, 1 15-17. 



PI- SS? line i, fig- 1- 



PI. trochiformis, line a, figs. 16, i 2-4, m 1. 



PI. trochiformis var. elegans, line a, fig. 15. 



PI. minutus, line a, figs. 8-13, c 2-4, d 12-16. 



PI. costatus (var. major Hilg.), line b, fig. 15. 



PI. parvus, line a, figs. 6-7, 20-22. 



PI. "IS^ {parvus Hilg. pars.), line k, figs. 1-4, 11. 



PI. crescens, line a, figs. 1-5, 17-19, 23, b 16-17, c 9-16, i 10-14. 



PL. "^S"*" ("^ar. revertens Hilg.), line k, figs. 5-10, m 10-14, p 6-14. 



PL oxystomus, line a, figs. 14, b 1-14, c 1, 5-8, k 12-18, 1 1-8, m 2-9, o 2, 



PL supremus, line 1, figs. 12-14, n 1-7,- o 3-12, p 1-5. 



p7 ^^„„*^^,.o-o- „^„J,.7,„.-., i:_-l ^^rt 4-11. 

 P . 0, 1. 



