Spirifera foggi. 



Fig. 28-31. Dorsal, front, ventral and profile view of a specimen. Page 117 



Orthis hybrida. 

 Fig. 32-35. Dorsal, ventral, front and profile view of a specimen. Page 39 



Trematospira helena. 

 Fig. 40-43. Dorsal, ventral, profile and front view of a specimen. Page 137 



Rhynchonella rugaecosta. 



Fig. 48-51. Dorsal, front, ventral and profile view of a specimen ; all 



enlarged xi. Page 78 



Orthis elegantula. 



Fig. 52-57. A series of specimens showing variations in size. Page 37 



Rhynchonella cuneata, var. americana. 



Fig. 58, 59. Dorsal and ventral view of a specimen. Page 85 



Fig. 62, 63. Front and profile view of a specimen. 



Cyrtia exporrecta, var. arrecta. 



Fig. 60, 61. Profile and cardinal view of a specimen. Page 94 



Atrypa calvini. 



Fig. 64-66. Profile, ventral and dorsal view of a specimen. Page 89 



