PLATE XII. 

 Ptychobesma Knappiana H. & W. 



Page 192. 

 Figs. 1, 2. A right valve and cardinal view of a specimen. 



" 3, 4, 5. Eight, left and cardinal views of another individual. 

 Fig. 6. An enlarged view of the hinge area of specimen, fig. 2, showing the 

 striated cartilage area ; the internal hinge plate is unknown and this 

 figure is not intended to represent it. 



Grammysia (Leptobomus) secunba var. gibbosa H. & W. 



Page 199. 

 Figs. 7, 8. Cardinal and left views of the specimen. 



Cardiopsis crassicosta H. & W. 



Page 188. 

 Fig. 9. A right valve of the species. 



Lucina (Paracyclas) lirata Conr. 



Page 200. 

 Figs. 10, 11, 13. Views of right and left valves of specimens presenting the ordi- 

 nary features of the species. 

 Fig. 12. A small individual showing unusually fine concentric ridges. 



Lucina (Paracyclas) elliptic a Hall, var. occibentalis H. &W. 



Page 189. 

 Figs. 14-16. Left, right and cardinal views of a well-preserved specimen of 

 large size. 



