ANTHOZOA—TETRACORALLA. 79 



67. A. tubaeformis Goldf. (Fig. 124.) Devonic. 

 Larger than preceding, with corallites crowded and occasionally 



uniting laterally. 



In the Hamilton beds of New York, Canada, etc. 



68. A. cornuta Bill. (Fig. 125.) Devonic. 

 Less crowded, mouths of corallites about twice as large as pre- 

 ceding. 



Onondaga and Hamilton of Canada, etc. 



Fig. 126. Romingeria umbelli- 

 Fig. 125, a-c. Aulopora cornuta (after Billings), fera (after Billings). 



XXXI. Romingeria Nicholson. 

 Auloporoid tubes with the buds given off in a verticil. Remote 

 tabulae, and occasional mural pores present, growth erect. Sil.-Dev. 



69. R. umbellifera (Billings). (Fig. 126.) Devonic. 

 Tubes about 1 mm. in diameter, delicately annulate by growth 



lines. Verticils from 6 to 12 buds, remaining at first close to- 

 gether, then bent rather abruptly outward radially. 



Onondaga limestone of New York, Canada, Michigan, etc., and 

 Hamilton group of Michigan. 



XXXII. Ceratopora Grabau. 



Coral like Aulopora in appearance, but tubes often much larger, 

 and never attached except at the base. Walls thickened by the 

 formation of coarse cysts, from the surfaces of which sharp spines 

 arise. Central space commonly open, the individual corallites re- 

 maining connected. Epitheca generally well marked. Devonic. 



70. C. jacksoni Grabau. (Figs. 127, 128.) Middle Devonic. 

 Branches budding at irregular intervals, tubes large and coarse, 



with longitudinal striation, marking the epitheca. Cysts coarse 

 and irregular. 



In the Hamilton group of New York, Michigan, etc. 



