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



very clearly a fissi- 



Fiff- 6. 



a, autopore ; m, mesopore j 

 /, fission. 



These projections appear to indicate 

 parous mode of growth in such cells. 



In drawing attention to the sub- 

 stitution of the generic name Fistu- 

 lipora for that of Gallo'pora^ to 

 which latter genus Prof. Schliiter 

 assigned the present species, we 

 have only to observe that there 

 exists a well-marked distinction 

 between the two genera, which 

 may be briefly stated as follows : — 

 In Fistulipora^ as has been shown 

 above, the mesopores are crossed 

 by imperfect tabulaa, which, coales- 

 cing, form a vesicular tissue ; in 

 Calloporttj on the other hand, the 

 tabulation of the mesopores is not 

 essentially different from that of 

 the autopores, except that the 

 tabulae are much more numerous in 

 the former cells than they are in the 



latter. The mesopores in Callopora are further, as a rule, 

 bounded by perfect walls. It is scarcely necessary to point 

 out that the structure of the present form accords with that 

 of Fistulipora and not with that of Callopora. 



Fistulipora eifeliensis stands alone in the remarkably large 

 size of its corallites, which exceed in their dimensions those of 

 any other species of Fistulipora with which we are acquainted. 



Formation and Locality. Not uncommon in the Middle 

 Devonian of Gees, near Gerolstein, Eifel. 



Fistulipora trifoliata, Schliiter. (PI. XVIII. figs. 1-1 c.) 



Fistulipora trifoliata, Scliliit. Sitzungsberichte der niederrlieinischen 

 Gesellschaft in Bonn (Naturwissenschaftliche Section), p. 147, 

 May 11, 1885. 



Corallum hemispherical, growing on the shells of mollusks 

 and other foreign objects. Surface not well preserved in any 

 of the specimens examined, apparently smooth. Corallites 

 extremely minute, barely distinguishable by the naked eye. 

 "Macule" distant from each other from 3 to 4 miljim. 

 About six of the autopores fill the space of 1 millim,, while 

 some of a larger size invest the " maculae." On looking at a 

 tangential section (figs. 1 a,lh) it is found that the autopores 

 have their outline interrupted by the very strong folds in their 

 walls, which impart a distinctly trifoliate aspect to them. 

 The free edges of the folds sometimes extend far into the lumen 



