Manual of the Paleontology of the Cincinnati Group. 



MANUAL OF THE PALEONTOLOGY OF THE 

 CINCINNATI GROUP. 



By Joseph F. James, M. D., M. Sc., F. G. S. A., Etc. 



Part VII. 

 (Continued from p. 88.) 



Monticaliporoidea (concluded) . — Echinodermata. 



MONTICULIPORA. 

 SUB-GENUS A. 



dekayia Edw. & Haime, 1851. 



Corallum branching, with corallites of two kinds, the larger ones 

 polygonal with thin walls and with well developed tabulae; smaller 

 tubes with thickened walls, isolated by the larger ones, and appearing 

 at the surface as so many detached, blunt, spine-like processes, placed 

 at the angles of junction of larger tubes. (Pol. Foss. des Terr. Pal. 

 1851, p. 277. Nicholson, Pal. Tab. Corals, 1879, P- 2 9 l ) (Dekay- 

 ella Ulrich, Jour, Cin. Soc. Nat. Hist. vol. 5, 1882, p. 155.) 



Remarks. — This sub-genus can only be separated from Monticuli- 

 pora proper by the surface columns, which constitute a marked feature 

 of the exterior. Mr. Ulrich's Dekayella can not be regarded as dis- 

 tinct. In his latest publication (Pal. of Minnesota, vol. 3 of Geol. 

 and Nat. Hist. Survey, 1893, P- 2 ^9) ne gives in substance the follow- 

 ing description : Corallum ramose; branches cylindrical or compressed; 

 calices angular or rounded, their shape depending upon the number 

 and disposition of the interstitial corallites ; these are more or less 

 numerously distributed among the larger calices and aggregated into 

 irregular clusters, or they may be wanting except in the clusters or 

 even absent nearly altogether; spiniform tubuli of all sizes, the larger 

 ones commencing in the axial region, the smaller ones more abundant 

 and developed in the peripheral region only ; tabulae horizontal, 

 numerous. 



In his remarks upon the genus Mr. Ulrich states that it might be 

 well to unite Dekayia, Dekayella and Heterotrypa (as restricted by him) 

 into one, for the reason that there are so many intermediate forms. 

 He eventually concludes, however, to keep them distinct. 



