500 Dr. H. A. Nicholson and Mr. A. H. Foord on 



Genus Fistulipoea, JVrCoy, 1849, emend. 

 Nicholson & Foord. 



Corallum varionslj shaped, dimorphic ; consisting of two, 

 more rarely of three, kinds of corallites ,* the first series 

 (autopores) of a cylindrical or subcylindrical form with distinct 

 walls, which on one side are thrown into two more or less 

 well-developed longitudinal folds, giving to the cross section 

 of the tube a characteristic trifoliate form. Apertures with 

 raised margins, and prominent arched lips on one side corre- 

 sponding with the folds. Tabulee numerous, horizontal. The 

 second series (mesopores) generally numerous, with imper- 

 fectly developed walls and very abundant tabulse, which by 

 their coalescence give rise to a vesicular tissue *. The third 

 series (acanthopores) , sometimes absent, consist of very minute 

 tubuli, situated at the angles of junction, or in other parts 

 of the thickness of the walls of the autopores and meso- 

 pores ; they have distinct cells, are devoid of tabulse, and pro- 

 ject from the surface of the corallum in the form of blunt 

 spines. No mural perforations. 



Type : Fistulipora mcrustayis, Phillips, sp. 



F{stuli2Jora incrustans^ Phill., sp. 

 Calamopora incrustans, Phillips, Geology of Yorkshire, part ii. p, 200, 



pi. i. figs. 63, 64 (1836). 

 Berenicea megastoma, M'Cov, Synopsis of the Oarhoniferous Fossils of 



Ireland, p. 195, pi. xxvi. iig. 13 (1844). 

 Fistulipora minor, M'Coy, Ann. & Mag. Nat. Hist. ser. 2, toL iii. p. 130 



(1849) ; id. Brit. Pal. Foss. p. 79 (1851). 

 Ceramopora megastoma, Vine, Quart. Journ, Geol. Soc. Tol. xxxvi. 



p. 359, pi. xiii. (1880). 

 Ceramopora {Berenicea) megastoma, John Young, Ann, t& Mag. Nat. 



Hist. ser. 5, vol. x. p'. 427 (1882). 

 \]^ on Fistulipora minm; Nich. Pal. Tabulate Corals, p. 306 (1879).] 



Spec. char. Corallum incrusting, growing upon the stems 

 of Crinoids or other foreign bodies, and in the initial stages 

 of growth taking the form of small circumscribed patches, 

 often of a circular form. Adult crusts usually from 1 to 2 

 millimetres or more in thickness, the corallites being often more 

 or less reclined in the young crusts, but becoming erect in old 

 examples. The mode of growth is from definite centres 

 (primitively one) , from which the corallites radiate, and which 

 ultimately constitute so many stellate " maculse." The auto- 

 pores average \ millim. in diameter, and are slightly but quite 

 distinctly trifoliate in section. The apertures in well-pre- 

 served specimens show very clearly the arched lip, which 

 depends upon the trifoliate form of the tubes. About three 

 autopores occupy a space of Ig millim. ( = to about fifty auto- 

 * See note p. 516. 



