Vol. 65.] CARBONIFEROUS LIMESTONE OF COUNTY CLARE. 577 



Zaphrentis vaughani, sp. nov. (PL XXVII, fig. 11.) 



Description. — Form conical or slightly cornute ; epitheca ex- 

 hibiting longitudinal striations and faint annular lines of growth. 



Horizontal section. — The cardinal fossula, which is situated 

 on the concave side of the corallum, is not well marked in the 

 lower part of the coral, but in sections taken higher up is well 

 defined and extends to the centre, the two septa which bound it 

 being almost parallel. Just below the floor of the calyx the inner 

 end expands rapidly. A counter-fossula is not developed. The 

 septal arrangement is almost radial, though a slight curvature 

 towards the fossula is sometimes noticeable. The major septa are 

 strong, and their inner ends become fused together into a compact 

 mass, giving the coral a densiphylloid appearance. 



The cardinal septum at first completely divides the fossula, but is 

 seen to become rapidly shorter as the sections approach the calyx- 

 floor. The counter-septum is readily distinguished by the fact 

 that the minor septa on each side of it are strongly developed and 

 reach the central fused mass. These, at first sight, simulate major 

 septa, but their true nature is easily recognizable on closer examina- 

 tion of the wall. The remaining minor septa, though rudimentary, 

 are conspicuous even in the early stages of growth ; towards the 

 upper part of the corallum they project inwards a short distance 

 from the wall. 



The tabular intersections, which are rather numerous, are evenly 

 spaced, and preserve a regular concentric arrangement. 



Discussion. — This coral occurs rarely in Z x of County Clare, but 

 has not been previously recorded from Great Britain ; Mr. Carru- 

 thers informs me that he has a single specimen from Tournai 

 in Belgium. 



In the position of the fossula on the concave side of the corallum, 

 the curvature of the major septa convex to the fossula, the rapid 

 dwindling of the cardinal septum on approaching the calyx-floor, 

 and the absence of a counter-fossula, it bears some resemblance to 

 Zaphrentis delanouei, M.-Edw. & H., but is readily distinguished from 

 that species by the fusion of the major septa, the greater number 

 of tabular intersections, and the abnormal development of the minors 

 on either side of the counter-septum, although the last feature is 

 sometimes noticeable to a less extent in Z. delanouei. 



Zaphrentis sp. (PL XXVII, fig. 4.) 



This form is represented by a single specimen from the top of S 2 . 

 Its relations are necessarily somewhat obscure. 



In its longitudinally striated epitheca and the presence of the 

 fossula on the concave side of the corallum, it is apparently related 

 to Zaphrentis ennishilleni. The fossula in the lower part of the 

 corallum has, however, almost parallel sides, and is completely 

 bisected by the cardinal septum. In higher sections, this septum 

 dwindles rapidly in length, and the fossula expands widely at its 

 inner end', having a thick stereoplasmic lining as in Zaphrentis 

 Tconincki. 



2r2 



