PLATE XX. 



Zaphhentis Halli. 



Zaphrentis Halli Edw. -Haime. Polyp. Poss. des Terrains Palaeozoiques, p. 341. 1851. 

 Compare " (/iguiitea Edw. -Haime. Polyp. Foss. des Terrains Palfeozoiquea, p. 340. 1851. 



Fig. 1. A transverse section acro.ss tlie lower part of a specimen showing the broad diaphragms, 

 the lateral fosset, and also the extent of the lamelke. 



I'ig. 2. View of the broad shallow cup of a small specimen, having the fosset on the riglit side. 



Fig. 3. A short broad form, with a deep cup and external fosset. The specimen has a broad ex- 

 panded foot-like base, by which it has been attached to soma foreign body. 



The specimen is referred to this species with some doubt of its positive identity. 



Fig. 4. The interior of the cup of another specimen, an inch and a quarter in depth, the fosset ex- 

 ternal. 



Fig. 5. Transverse section of a large specimen, shovving the extent of the lamelte and the inter- 

 lamellar partitions, as well as the broad transverse diaphragms. 



Fig. 6. Lateral view of a large specimen, with deep, narrow cup. A part of tlie rim lias been 

 broken off. 



Fi^'. 7. Lateral view of a shorter and broader form than the preceding. 



Fig. 8. A longitudinal section, showing the crowded transverse diaphragms. 



Fig. 9. The interior of the cup of a medium sized specimen. 



Hamilton group, Skaneateles Lake and vicinity. 



