OF PLANORBIS AT STEINHEIM. 107 



PI. tenuis, line c 2-12, 15-18, d 6-17, e 1-15, k 11, o 8-10. 



PI. discoideus, line f 4-17, g 1-14, li 1-12, i 1-12, k 1-5, 12, 1 1-10. 



PI. discoideus var. iiivolutus, line d 18, e 17-19. 



jPi- 'SL^Sf line k 7. 



-P^- 'XSSi" Cvar. eleffans Hilg.), line k 6. 



PI. trochiformis, line k 8-10, 1 1-12. 



Stratum a 2, Second Hole, Old Pit, Section 6. 



PI. Steinheimensis vai*. aequiumbilicatus, line m 1-7. 

 PI. Steinheimensis, line m 8-11, n 1-5. 



PI oximomm lijjg ^ 12-14. 



PI. tenuis, line n 7-12, 14-15, o 1-7. 

 PL discoideus, line o 8-16, p 1-13. 

 JPi- ''SS" line o 15. 



Plate II. 



Magnified 2 diameters. 



List of Species. 



PL Steinheimensis var. aequiumbilicatus, line a 1-2. 



PL Steinheimensis, line a 3-4. 



PL Kraussii, line d 1-17, f 9. 



I'l- s.eiSt^, line a 7-8, q 12. 



PL tenuis, line a 5-6, 9-12, e 18-27, f 1-8, 10-12, p 9-18, q 5-11. 



PL discoideus, line a 13, b 1-6, 16, c 1-13, f 13-19, li 1-18, i 1-14, k 1-2, m 3-4, 6-9, n 1-7, q 13-16. 



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



PI- SJJSr line m 1-2, 5, q 17-18, r l-A. 



PL trochiformis, line b 7-10, d 18-19, k 3-11, 1 1-11, n 8-12, o 15-18, r 5-10, s 1-8. 



PL trochiformAs {yw. pyrguliformis Sand.), line s 9-12. 



PL discoideus (young with forms similar to rotundatus Hilg.), line h 19-23. 



PL trochiformis (young of normal varieties identical with rotundatus Hilg.), line o 1-14, p 1-8. 



PL minutus, line e 1-5, 7-8, g 1-2, 4, p 14r-20, b 11-15. 



PI- "SSr line e 10-12, g 6, q 1. 



PL denudatus, line e 13-14, g 7-8. 



PI- S?£, line e 6, g 5. • 



PL costatus, line e 9, g 3, q 2-4. 



PL "SJ;" line e 15-17. 



PL triquetrus, line g 9-23. 



Check List by Lines. 



Line a, figs. 1-2 PL Steinheimensis var. aequiumbilicatus, 3-4 PL Steinheimensis, 5-6 PL tenuis, 6-8 

 P^- steiiSSensis, 9-12 PL tcnuis, 13 PL discoideus. 



Line b, figs. 1-6 PL discoideus, 7-10 PL trochiformis, 11-15 PL minutus, 16 PL discoideus. 



Line c, figs. 1-13 PL discoideus. 



Line d, figs. 1-17 PL tenuis var. Kraussii, 18-19 PL trochiformis. 



Line e, figs. 1-5 PL minutus, 6 PL SS, 7-8 PL minutus, 9 PL costatus, 10-12 PL "SSST 1^-14 PL denu- 

 datus, 15-17 PL Xlgf 18-27 PL tenuis. 



Line f, figs. 1-8 PL tenuis, 9 PL tenuis var. Kraussii, 10-12 PL tenuis, 13-19 PL discoideus. 



