148 Dublin Microscopical Cluh. 



MyUusia Grayi. — Octahedral nodes of the skeleton, in compa- 

 rison with those of Dactylocalyx pumiceus in the young state, were 

 shown by Prof. Sollas. 



Ctenodrilus, sp., a living example, was shown by Prof. Haddon. 



December 18, 1884. 

 Plant-remains from Silurian Mocks. — Prof. Sollas showed a sec- 

 tion from Silurian rocks presenting what seemed to be plant- 

 remains, forming, in a longitudinal view, long drawn out, large, and 

 thick-walled, variously sized non-septate tubes, and in a transverse 

 view presenting each a circular outline, these involved in a common 

 matrix. 



Section of Quartz-tracliyte, or Liparite, from the NeighhourTiood of 

 Sviyrna, was shown by Prof. Hull, P.R.S, The district is well 

 known to be rich in volcanic rocks of Tertiary age, consisting of 

 trachytic, augitic, and other varieties of rock,-^ together with tuffs and 

 agglomerates, on a mass of which last the ancient castle is built. 



The section exhibited is taken from a grey porphyritic rock, con- 

 taining numerous crystals of sanidiue, plagioclase, minute grains 

 of quartz, crystals of biotite, augite, hornblende ?, sub-crystalline 

 forms of vesuvian, and magnetite in small quantity in octahedral 

 grains — in aU about eight varieties of minerals set in a "ground- 

 mass " (or paste) of glass. 



The ground-mass requires a rather high power for observation, 

 and is seen to consist of a glass traversed by multitudes of trichites 

 and microliths, together with minute colourless prisms of apatite, 

 quartz grains, and crystals of plagioclase. The quartz grains, both 

 large and small, are also seen to contain numerous cavities, some 

 with fluid, some containing " dust" or specks of magnetite (?), 



From the above account it will be inferred that, with the polari- 

 scope, the section offers a very beautiful appearance, the various 

 minerals displaying their coloration with ever varying effects as the 

 polarizer is made to rotate. 



On the whole it would appear that the rock an.swers pretty well 

 to the description of " Liparite " of Eoth, as given by Zirkel 

 ( ' Mineralien und Gesteine,' p. 345) and Eosenbusch (' Mikro- 

 scopische Physiographie d. Mineralien,' Band ii. p. 138). 



RemarTcahle Spore or Spore-liTce Body from tlie Garhoniferous For- 

 mation. — Prof, Haddon exhibited a spore or spore-like body found in 

 a section from the Carboniferous formation, Halifax, forming a very 

 pretty object, much resembling some desmidian zygospore in its orbi- 

 cular figure, beset all over by numerous short processes of equal 

 length, causing the whole to present a stellate aspect. 



Spha^rohlasts from Stem of Privet (Liyustrum vidyare). — Dr. 

 M'Nab exhibited a section of an arrested bud from the stem of 



