GENERA OF FAVOSITID.^. 6i 



diminished in number, and there is much nearer approach to a 

 general equality in the size of the corallites. This distinction 

 will be at once evident on a comparison of transverse sections 

 of these two forms (PI. I., fig. 7, and PI. II., fig. 2 a). 



Favosites Forbesi, var. JValdroneiisis, has been beautifully 

 figured by Professor Hall {loc. cit.), with a doubtful reference 

 to F. Forbesi, E. and H. ; but, so far as I know, no description 

 of it has been published. In its internal structure there is no 

 feature of special importance to note, save that there seem to 

 be no traces of septal spines, and the tabulae are perhaps more 

 regularly distributed and less flexuous than in the normal form 

 of the species. Professor Hall has figured the tubes with 

 biserial mural pores — and so far as I have observed, this is the 

 general arrangement ; but there may be an additional row, and 

 the pores seem to be close-set, and somewhat irregular in their 

 distribution. 



Favosites Forbesi, E. and H., var. Eifelensis, Nich. 

 (PI. II., fig. 3, and PI. III., figs. I - 1 Ik) 



Corallum forming spheroidal or pyriform colonies, from half 

 an inch up to two inches in diameter, but generally an inch or 

 rather more across. Corallites irregularly prismatic, or with 

 rounded angles, and more uniform in size than in typical forms 

 of the species, the larger ones being numerous, but mostly 

 attaining a diameter of no more than a line or three-quarters of 

 a line, while the small tubes are much reduced in numbers. 

 Septa exceptionally well developed, and extending for a con- 

 siderable distance into the interior of the visceral chamber, in 

 the form of strong blunt spines. Tabulae horizontal or slightly 

 flexuous, about six or seven in the space of two lines. Mural 

 pores numerous, close-set, apparently biserial or triserial. 



I propose this name for a small Favosites which I have 

 found to be tolerably plentiful at Gerolstein in the Eifel. Its 

 general appearance (PI. HI., fig. i) is so closely similar to that 

 of medium-sized specimens of F. Forbesi from the Upper 

 Silurian, that the near relationship of the two forms is beyond 



