Vol. 52.] FROM THE CARBONIFEROUS LIMESTONE. 447 



They are present in the basal as well as in the lateral and marginal 

 portions of the corallum, and they closely correspond to those in 

 P. cuneiformis and P. humilis. There are no indications of a porous 

 or lacunar ccenenchyma. This specimen is smaller and the surface- 

 ridges are somewhat finer than in the Indiana examples of the 

 species. De Xoninck 1 has already recorded the occurrence of this 

 form in the beds at Hook Point. — May 18th, 1896.] 



The genus Palceacis, accepting P. cuneiformis, M.-Edw., as the type, 

 appears to represent a distinct family of perforate corals in some 

 features more nearly allied to the Favositidae than to the Madre- 

 poridae or Poritidae. Thus, for example, with respect to the per- 

 foration both of the bases as well as the sides of the corallites by 

 mural pores and canals, we find a similar condition of things in 

 Pleurodictijum granuliferum, Schliiter, 2 from the Middle Devonian 

 of the Eifel, and this moreover is quite a free form. 



By the removal of Hydnopora (?) cyclostoma, Phill., from Paloeacis 

 this form must represent an independent genus for which I venture 

 to propose the name of Microcyathus. Ferd. Rcemer 3 considered 

 that it might be included under Ptychochartocyathus, Ludwig, 4 but 

 if any reliance is to be placed on the description and figures of the 

 type of this genus, P. laxus, Ludwig, there is certainly no generic 

 relation to Hydnopora (?) cyclostoma, Phill. Ludwig states posi- 

 tively that P. laxus has thick non-perforate walls, no mention is 

 made of a lacunate ccenenchyma, and, judging from the figure, 

 there is no resemblance in its mode of growth and the disposition 

 of the calices to H. (?) cyclostoma, Phill. 



In this connexion it will be desirable to mention another coral, 

 the Astrceopora antiqua, M'Coy, 5 from Hook Point, Wexford, which 

 -has been regarded as a synonym of H. (?) cyclostoma, Phill. I have 

 not seen the type-specimen, but examples from the same locality as 

 the type, which correspond with M'Coy's figures, are in the Jermyn 

 Street Museum, and through the kindness of Mr. E. T. Newton, 

 F.R.S., a section has been prepared from one of these, which I have 

 examined. The calices are very shallow, and the walls apparently 

 • consist of compact tissue, in which there are some irregular tubes — 

 as if due to some boring organism. The section was not altogether 

 clear, but there were no indications of a lacunar intermediate 

 tissue between the calices as in Microcyathus {Hydnopora ?) cyclo- 

 stoma, and it is evidently generically distinct from this latter. 



In conclusion I wish to express the great obligations under which 

 I am to the Rev. G. C. H. Pollen, S J., F.G.S., for supplying me with 

 the specimens of Pal&acis humilis, and I am glad to state that this 

 gentleman intends presenting the type-forms to the British Museum 

 (Natural History). 



1 'Nouv. Kech. Anira. Foss. Terr. Carb. Belgique,' pt. i. 1872, p. 158. 



2 ' Anthozoen des rheiniscben Mittel-Devon,' Abhandl. k. preuss. geol. Landes- 

 anst. 1889, p. 193, pi. iv. figs. 5-8. 



3 ' Letbaja Paloeozoica,' Atlas, 1876, pi. xxxix. Explanation. 



4 Palaontographica, vol. xiv. (1866) pp. 189, 231, pi. xlvii. fig. 14, & pi. lxix. 

 £g. 2 a. 



5 • Syn. Carb. Limest. Foss. Ireland,' 1844, p. 191, pi. xxvi. fig. 9. 



