ANTHOZOA—TABULATA. 



85 



by twelve longitudinal furrows and by granulations. Tabulae 

 granulose, with their margins deflected into 12 (=b) pits or notches 

 corresponding to the longitudinal furrows, marginal pores com- 

 monly in more than two rows. 



In the Niagara group of New York, Ontario, Michigan, Wis 

 consin, Iowa, and the Falls of the Ohio region. 



84. F. niagarensis Hall. Siluric. 

 Tubes much smaller than in the preceding species (about 1.5 



mm. in diameter), tabulae rarely notched at margin ; mural pores 

 scattered near the angles of the tubes. Inner surface of tubes deli- 

 cately spinulose. 



In the Niagara group of New York, Ontario, Michigan, Iowa 

 and Kentucky. 



85. F. helderbergiae Hall. (Fig. 138.) Lower Devonic. 

 Heads lenticular or hemispherical, often large, and with the base 



covered by a strongly wrinkled epitheca. Calices about 1.5 mm. 

 in diameter with strong longitudinal ridges. Mural pores in one 

 or two rows, with elevated rim. Tabulae close. 



In the Lower Helderberg beds of New York and at Cumberland, 

 Md. 



86. F. winchelli Rom, Devonic. 

 Tubes much as in F. favosus, but with the marginal notching 



rare. Not infrequently the whole rim of the septum is turned 

 down. Interior of tube with twelve well-marked longitudinal 

 furrows, without squamae. 



Fig. 138. Favosites helderbergice (reduced) with a group of corallites enlarged 



(Pal. N. Y.). 



