PAGB. 



Figs. 30 to 33 BUCANIA FRANKFORTENSIS Ulricb 891 



Pour -views of the silicifled shell upon which the species is founded. Top of Tren- 

 ton group, Frankfort, Kentucky. The specimen has suffered from maceration, 

 consequently the surface markings, the interrupted revolving lines especially, 

 are more or less obscure. 



Figs. 34 and 35 BUCANIA PERACUTA Ulrich 896 



Two views of the incomplete type of this remarkable species. Trenton group, 

 DeKalb county, Tennessee. 



Figs. 36 to 40 BUCAJJIA NASHVILLENSIS Ulrich 890 



36 Basal view of a macerated specimen from the Trenton at Nashville, Tennessee, 



possessing unusually thick inner lip. 



37 Apertural view of another specimen from this locality. 



38 and 39 Two views of an incomplete but otherwise well preserved shell from DeKalb 

 county, Tennessee, showing form of aperture, the slit and surface markings. 



40 Small part of dorsal surface of same showing the slit-band and surface markings. 



Figs. 41 to 44 - BUCANIA NANA Ulrich 895 



41 Lateral view of an average specimen of this small species. 

 42 and 43 Apertural and lateral views of same, x2. 



44 Part of the dorsal surface of another specimen, x3, showing exceedingly delicate 

 striae connecting the regular transverse lines. The line at the bottom of the 

 figure shows the convexity of the dorsal surface. Trenton group, near Burgin, 

 Kentucky. 



Figs. 45 and 46 BUCANIA NANA var. SUBPATULA Ulrich 896 



Lateral view, X 2, and dorsal view of the natural size of a specimen of this variety, 

 showing a smaller umbilicus and wider aperture than pertains to the typical 

 form of the species. Near Burgin, Kentucky. 



Fig. 47 BUCANIA SINGULARIS Ulrich 894 



Dorsal view of a specimen that is largely overgrown by a delicate bryozoan, 

 obscuring the finer surface markings. Upper part of Trenton group, Nash- 

 ville, Tennessee. 



