78 PROCEEDINGS OF THE 



regard it as the same, as it agreed in all essential particulars* 

 except those which would naturally arise out of differences in the 

 form and structure of the kind of organism penetrated. To dis- 

 tinguish the Carboniferous form from that already described, he 

 proposed to call it Palaeachlya perforans, var. carbonaria, as it 

 appears to have been a little more robust than the older form. 



Mr. James Neilson, jun., also showed an interesting series of 

 Chonetes Laguessiana from Roscobie, Fifeshire, which, under the 

 partly eroded surface of the outer shell, showed numerous perfora- 

 tions of, apparently, the same boring alga. Mr. Young had also 

 found it in the shell structure of Productus costatus, a Carboni- 

 ferous limestone fossil, as well as the last named. 



April 29th, 1879. 



Professor John Young, M.D., F.G.S., President, in the chair. 

 Mr. John Smith, Stobbs, Kilwinning, was elected a correspond-, 

 ing member, and Mr. Christopher Sherry an ordinary member. 



SPECIMENS EXHIBITED. 



. Mr. John Young, F.G.S., exhibited a series of Conodont re- 

 mains and Sponge Spicules from the Silurian and Devonian lime- 

 stone strata of England, forwarded by Mr. John Smith, Kilwinning, 

 corresponding member, who had sent for exhibition, at a former 

 meeting of the Society, an interesting series of conodonts and 

 various forms of sponge spicules, which he had found in the lime- 

 stone strata around Dairy, Ayrshire. Since that time Mr. Smith 

 had visited several districts in England, and had been successful 

 in discovering the remains of conodonts in some of the weathered 

 shales and limestones of the localities he had visited, and which 

 curious remains had not, so far as he knew, been formerly noted 

 as occurring either in the Silurian or Devonian formations of 

 England. Yery little is yet known of the nature of the organisms 

 that have yielded these conodont remains, which consist of small 

 teeth, jaws, &c, of many different forms, one authority referring 

 them to the jaws of annelides, another to those of myxinoid fishes, 

 or to the lingual armature of certain forms of mollusca or the 



