PLATE 133—Continued. 
30. Anterior view of a large corallum. Collection of Mr. Nettelroth. 
31. View of the calyx of a corallum. Collection of the author. 
From the ferruginous clay of the Lower Devonian, near Louisville. 
ZAPHRENTIS UNGULA. Devonian. 
32. Posterior view of a corallum, from the Lower Devonian rocks, 
Falls of the Ohio. 
33. Left lateral view of a corallum, from the same place. 
34, Anterior view of a slender corallum of unusual. altitude, with lami- 
nated structure obscured by the deposition of silica in annular 
dots during fossilization; from the ferruginous clay of the Lower 
Devonian, near Louisville. 
35. View of the calyx of a corallum, from the horizon and neighbor- 
hood of the preceding specimen. 
Collection of the author. 
