PLATE XXVIII. 



Zaphrentis complanata. 

 Page 430. 

 Fig. 1. Posterior view of the specimen, showing the interior of the calyx. 



Zaphrentis cyathiformis. 

 Page 431. 

 Fig. 2. Lateral view of a specimen. 

 Fig. 3. Calicular view of the same. 



Zaphrentis ponderosa. 

 Page 431. 

 Fig. 4. A posterior view, looking into the calyx. The specimen is slightly 

 twisted in its mode of growth. 



Zaphrentis corrugata. 

 Page 431. 

 Fig. 5. Lateral view of a specimen. 

 Fig. 6. View of a fragment, showing the interior of the cup. 



Zaphrentis subcompressa. 

 Page 432. 

 Fig. 7. Lateral view of a specimen. 

 Fig. 8. The calyx of another specimen. 



