44 The Irish Naturalist. 



The seventh table is also of black marble, but is relieved 

 more uniformly by fossil-sections. It is from the Kilkenny 

 quarries, the history of which is associated with that of the 

 energetic famil}^ of Colles. Grey sections of detached and 

 unbranching corals are seen everywhere, their septa being 

 beautifully preserved ; they probably represent Zaphrentis 

 rather than Cyathophylhim. One or two white remains of spiral 

 gastropods, probabl}- Euomphahis, also occur, with a section 

 of a turreted form. But the most interesting objects are the 

 conspicuous sections of a brachiopod, evidently a form with 

 external flutings, and with well-marked dental plates and a sep- 

 tum in the larger valve. These sections provide a pleasant 

 problem in reconstruction, such as will rejoice generations 

 of zoologists and geometricians at the luncheon-table. I 

 believe the shell to be a Cyrtiiia,'' many of the sections passing 

 horizontally across the upper part of the larger valve. We 

 thus have a convex and serrated line produced b}^ the section 

 of the outer part of the shell, with an indentation corresponding 

 to the external median furrow ; the internal median septum 

 is seen running inwards, soon dividing into two portions, 

 which are styled *' dental plates." These, however, are 

 often traversed by the section in the region of the broad 

 '* area," which runs from the beak to the hinge-margin 

 of the shell ; and hence the white line formed by each dental 

 plate is continued sharply awa}^ to right or left by the 

 straight section of the area, which closes in the front of 

 the shell and which unites with the edges of the serrated 

 part of the section. Here and there a vertical section 

 across the valve shows the median septum running on 

 below, and its two diverging portions enclosing a sort 

 of oval space above, the apex of which is in contact with the 

 beak. 



The geologist, at an}' rate, will no longer feel solitary 

 at his luncheon -table ; but, indeed, he is never likely to sit 

 long alone in this favoured home of quip and countercheck, 

 of wise saws and modern instances. 



■" Davidson, "British Fossil Brachiopoda ; Permian and Carboniferous 

 species," p. 68, and plate xiv., fig. 8. 



