546 DR WHEELTON HIND ON 



Fig. 12. Euthydesma alata, a left valve. Page 501. 

 Fig. 13. Leptodesma modiolaris, the right valve, from a cast. Page 498. 

 Fig. 14. „ „ the left valve. Page 498. 



Figs. 15, 15a. ,, ,, view of the left valve, intei-nal cast, and view from above. Page 498. 



Fig. 16. ,, ardmillanensis, a left valve. Page 497. 



Fig. 17. ,, transversa, a right valve, anterior and imperfect. Page 498. 



Fig. 18. „ „ a left valve. Page 498. 



Fig. 19. Byssonychia radiata, a right valve. Page 487. 

 Fig. 20. „ ,, the left valve of a bivalve example. Page 487. 



Fig. 21. ,, „ internal cast, left valve. Page 487. 



Fig. 22. ,, ,, right valve of a bivalve example. Page 487. 



Fig. 23. ,, angusta, a left valve, internal cast. Page 487. 



Fig. 24. „ „ a left valve. Page 487. 



Figs. 25, 25a. ,, sublcevis, the right valve. The shell has been drawn with the hinge line vertical 



with 25a, a view of the anterior end. Page 486. 



Fig. 26. Ambonychia triton, a left valve. Page 488. 



Fig. 27. „ „ a left valve. Page 488. 



Fig. 28. ,, amygdalina, a right valve, internal cast. Page 489. 



Fig. 29. „ ,, a right valve. Page 489. 



Fig. 30. „ undata, the left valve. Page 490. 



Plate II. 



Fig. 1. Ambonychia quadratus, a right valve. Page 490. 

 Fig. 2. „ „ a left valve. Page 490. 



Fig. 3 ,, ,, a right valve. Page 490. 



Figs. 4, 5. „ cuneata, left valves. Page 491 . 



Figs. 6, 6a,b. „ „ a bivalved example viewed from different aspects. Page 491. 



Figs.7,7a,&,c. ,, simplex, a bivalved example, viewed from different aspects. Page 491. 



Figs. 8, 9. ,, ,, right valves. Fig. 8, a cast of the interior. Page 491. 



Fig. 10. Myalina prisca, a left valve. Page 499. 



Fig. 11. Mytilarca (Plethomytilus) mytilimeris, a left valve. The shell is oriented incorrectly in the 

 drawing. The hinge line should have been horizontal. Page 516. 



Fig. 12. Mytilarca [Plethomytilus) mytilimeris, a right valve. Page 516. 



Fig. 13. Modiolopsis exasperatus, a bivalve example. Page 504. 



Fig. 14. „ ,, from a cast of the right valve. Page 504. 



Fig. 15. ,, ,, a bivalve example. Page 504. 



Fig. 16. „ subquadratus, a right valve. Page 504. 



Fig. 17. „ „ a left valve. Page 504. 



Fig. 18. ,, scotica, a left valve. Page 50 5. 



Fig. 19. ,, ,, var brevis, a right valve. Page 505. 



Fig. 20. „ „ „ the left valve. Page 505. 



Fig. 21. ,, expansa, a right valve. Page 503. 



Fig. 22. ,, minor, a right valve. Page 506. 



Fig. 23. „ „ a left valve. Page 506. 



Fig. 24. Mytilops subovalis, a left valve. Page 506. 



Fig. 25. „ ,, a right valve. Page 506. 



Fig. 26. Modiolodon subcircularis, left valve showing muscle scars. Page 508. 



Fig. 27. ,, ,, left valve showing exterior. Page 508. 



Fig. 28. „ quadratus, a right valve. Page 508. 



Fig. 29. „ „ a left valve. Page 508. 



Fig. 30. „ subovalis, a right valve. Page 507. 



Fig. 31. ,, ,, a left valve showing adductor muscle scars. Page 507. 



