PLATE III. 



Fig. i. An example of Favosites Forbesi, E. and H., var. Eifelensis, Nich., from 



the Devonian of Gerolstein in the Eifel, of the natural size. 

 Fig. i a. Portion of the surface of the same, enlarged twice. 

 Fig. i b. Vertical section of the same, enlarged five times, showing the septal 



spines, seen laterally and in cross-section, as well as the tabulae. 

 Fig. 2. A very young example of Favosites Forbesi, E. and H., var. tuberosa, 



Rom., from the Corniferous Limestone of Port Colborne, Ontario, of the 



natural size. The calices in the lower part of the corallum are closed by 



an epitheca 1 ! or opercular growth. 

 Fig. 2 a. Portion of the surface of a large and fully-grown example of the same, 



from the same locality, of the natural size. The lower calices have 



undergone closure by the epitheca. 

 Fig. 2 b. Portion of the surface of a large specimen of the same, from the 



Hamilton formation of Arkona, Ontario, of the natural size. 

 Fig. 2 c. Transverse section of a specimen of the same, from the Hamilton 



formation of Arkona, Ontario, enlarged five times. 

 Fig. 2 d. Part of a vertical section of the same specimen as the last, enlarged 



five times. Besides the tabulae proper, the section shows some of the 



peculiar transverse squamae, or incomplete tabulae, characteristic of this 



peculiar form. 

 Fig. 2 e. Portion of two corallites of a silicified example of the same, from the 



Corniferous Limestone of Port Colborne, Ontario, enlarged three times. 



The interior of the tubes exhibits the peculiar transverse squamae above 



alluded to, and the mural pores are also seen. 

 Fig. 3. Transverse section of Favosiles (Emmonsia) hemisphcerica, Yand. and 



Shumard., enlarged five times, from the Corniferous Limestone of Port 



Colborne, Ontario. 

 Fig. 3 a. Portion of one of the tubes of the same specimen, similarly enlarged, 



showing the close-set biserial mural pores. 

 Fig. 3 b. Portion of a vertical section of the same specimen, in which the 



tubes are quite empty, enlarged five times, showing the incomplete and 



flexuous tabulae. 

 Fig. 4. Portion of a transverse section of Favosites Bowerbanki, E. and H., 



from the Wenlock Limestone of Benthall Edge, enlarged five times. 



Several of the corallites show an incomplete division of their tubes by 



means of laminae directed inwards. 



Fig. 4 a. Transverse section of a single corallite of the same specimen, show- 

 ing incompleted fission, enlarged ten times. 

 Fig. 4 b. Part of a vertical section of the same species, from the Wenlock 



Limestone of Gotland, enlarged five times, showing the tabulae and mural 



pores. 



