{Proceedings Belfast Naturalists' Field Club.— Appendix, 1880-1881.) 





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SPONGE REMAINS FROM THE CARBONIFEROUS 

 LIMESTONE OF BEN BULBEN, CO. SLIGO. 



BY JOSEPH WEIGHT, F.G.S. 



(Read before the Belfast Naturalists' Field Club, on the \Zth April, 1881.J 



(j'^'JiFTER referring briefly to the several groups of sponges, and their posi- 

 JupL, tion in the animal kingdom, Mr. Wright proceeded to say, that having 

 a ~Q^ s> examined a portion of a pale yellow clay, which had been procured 

 near the summit of Bon Bulben Mountain by Mr. S. A Stewart, he found that 

 it contained an abundance of sponge-spicules, this being the only instance of 

 such remains having been found in Ireland in rocks of Carboniferous age. In 

 company of Mr. Stewart he had visited the spot for the purpose of ascertaining 

 the mode of occurrence of the sponge remains, and to procure a sufficient 

 quantity of the material for his investigations. Ben Bulben is a grand moun- 

 tain, 1,722 feet high, whose stupendous cliffs arrest the attention of the 

 traveller on the way from Bundoran to Sligo. The rock here may truly be 

 called mountain limestone, the entire range, of which Ben Bulben is the 

 most conspicuous, being composed of Carboniferous Limestone from the base 

 to the summit. Nowhere else in Ireland do the Carboniferous rocks attain so 

 great an elevation. Two days were spent on Ben Bulben, an ample supply of 

 the fossiliferous clay obtained, and also many rare fossils met with in the lime- 

 stone. Crinoids were especially abundant, notably the pretty little Pentre. 

 mites Derbiensis. The curiously branched coral, Cladochonus baccilaris, was 

 seen at one spot in great masses in the stone. The clay in question has been 

 under examination, and already has yielded eleven different forms of sponge- 

 spicules. Of these, four belong to the calcareous sponges, two to the Lithi- 

 stidae, and the remaining five to the group of the Hexactinellidae. Three of 

 these last-mentioned are extremely beautiful forms, being spirally ringed 

 spicules apparently referrible to one species of sponge, and new to science. 

 Mr. Wright further mentioned that some of the clay had been submitted to his 

 friend, Mr. James Cooke, of Cork, for chemical analysis, and was found to be 



