OF PLANORBIS AT STEINHEIM. 109 



Formation h, Section 6. 



PI. triquetriis, line g, figs. 17-23. 



PL discoideus, line h, figs. 1-18, i 1-14, k 1-2. 



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



PL discoideus (var. elatior Sand.), line i, figs. 15-17. 



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



PL discoideus, line m, figs. 3-4, 6-9. 

 PI- 'SS«;t line m, figs. 1-2, 5. 



Formation i, Section 6. 



Formation k, Section 6. 



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



PL trochiformis, line n, figs. 8-12, o 15-18. 



PL trochiformis (rotundatus-like young), line o, figs. 1-14, p 1-8. 



PL tenuis, line ji, figs. 9-13. 



Formation 1, Section 6. 

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



pj dtmdatus i;,,p f, fio- 1 

 -^ ^- tnimUus, ""'' 4' "6 '•' 



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

 PL tetiuis, line q, figs. 5-11. 



nj tenuis Ihip n fie 1'2 



PL discoideus, line q, figs. 13-16. 



I'l- 'SSef line q, figs. 17-18, r 1-4. 



PL trochiformis, line r, figs. 5-10, s 1-8. 



PL trochiformis (var. pi/rguliformis Sand.), line s, figs. 9-12. 



Plate III. 



Magnified 2 diameters. 



List of Species. 



PL discoideus, line o, 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- "S^Sr line i, fig. 1- 



PL trochiformis, line a, figs. 16, i 2-4, ml. 



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



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



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



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



PL "'i^"lf (parvus Hilg. pars.), line k, figs. 1-4, 11. 



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



PL. °'^iS'^' (v'^i"- ^evertens Hilg.), line k, figs. 5-10, m 10-14, p 6-14. 



PL oxystomu.% line a, figs. 14, b 1-14, c 1, 5-8, k 12-18, 1 1-3, m 2-9, o 2. _ 



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



PL oxystomus var. cochleatus, line 1, figs. 4-11. 



PL supremus var. turritus, line n, figs. 8-13, o, 1. 



