XX111 



Papy racea, 29. 

 Tuberculata, 30. 

 Striata.Zl. 

 Dactylus. 31. 

 Candida, 31. 

 Para*, 32,/. 71. 



XYLOPHAGA. 



Dorsalis, 32. 



GASTROCH^NA. 



Modiolina, 33. 



GALEOMMA. 

 Turtom,'33,f. 72. 



SOLEN. 



Vagina, 34. 

 Novacula, 3-5. 

 Kiliqua, 35. 

 .EV^'s, 35. 



Pellucidus, 35, f. 106. 

 Legumen, 36. 



Coarctatus,36. 

 Dechvis, 37. 

 Fragilis, 37. 

 Candidus, 38. 

 Scapula, 38. 



PANOP^A. 



Arctica, 38. 



Truncata, 40. 

 Arenaria, 40. 

 M. ? Decussata, 41. 



LYONSIA. TUR- 



TON (7J. 



fMya Norwegica, 



ANATINA. 



Truncata, 4'2. 

 Prtetenius, 43. 

 Distort a, 43. 

 Arctica, 42. 



(z) Transverse, inequi valve, inequilateral, open at the 

 anterior end. Hinge with a transverse heart-shaped 

 moveable tooth common to both the valves, and uniting 

 them by a transverse cavity in each; ligament internal. 



