PLATE I. 



Fig. i. Transverse section of a typical example of Favosites Gothlandica, Lam., 

 from the Wenlock Limestone of Gotland, showing the regular, polygonal, 

 thin-walled corallites, enlarged five times. 



Fig. i a. A vertical section of the same, similarly enlarged. A mural pore is 

 seen here and there. 



Fig. 2. Transverse section of a specimen of Favosites Gothlandica, v&r.favosa, 

 Gold., from the Hamilton Group (Devonian) of Erie Co., New York, en- 

 larged five times. Some of the corallites show the marginal foldings of 

 the tabulae as so many dark spaces. 



Fig. 3. Upper and under surfaces of an exceedingly young specimen of Favo- 

 sites Gothlandica, Lam., from the Wenlock Limestone of Dudley, of the 

 natural size. 



Fig. 4. Outline of part of the upper surface of the corallum of a specimen of 

 F. Gothlandica, var. favosa, Gold., from the Niagara Limestone of Mani- 

 toulin Island, of the natural size; and a single corallite enlarged four 

 times to show the marginal depressions or plications of the tabulae. 



Fig. 5. A few corallites of a specimen of F. Gothlandica, from the Niagara 

 Group of Manitoulin Island, with well - developed septal spines (Astro- 

 cerium of Hall), of the natural size, and one corallite enlarged four times. 



Fig. 6. Transverse section of Favosites Gothlandica, var. Billingsii, Rom., from 

 the Hamilton Group of Arkona, Ontario, enlarged five times. 



Fig. 7. Transverse section of an adult example of Favosites Forbesi, E. and H., 

 from the Wenlock Limestone of Stoke-Edith. enlarged five times. 



