Geological Society. 343 



may be regarded as the Palaeozoic representatives of Eozoon. Stro- 

 matopora occurs infiltrated with calcite or silica, or with its struc- 

 ture wholly or in part replaced by crystalline silica or dolomite. The 

 author concluded his first section with the characters of the genera 

 which have been included in the Stromatoporida). 



In the second part he noticed a number of facts relating to the 

 occurrence of hydrous silicates, of the nature of serpentine and 

 loganite, infiltrating paleozoic fossils and illustrating the mode of 

 occurrence and mineralization of Eozoon. Instances of this kind were 

 said to be exceedingly common, showing that such silicates, whether 

 originating as direct deposits from water, or as products of the de- 

 composition of other minerals, are efiicient agents in the infiltration 

 of the pores and cavities of fossils, and have played this part from 

 the earliest geological periods. 



4. " On some Devonian Stromatoporidce." By A. Champernowue, 

 Esq., F.G.S. 



The author's object in this note was to give some account of the 

 origin of a fine series of Stromatoporidae presented by him to the 

 Society. They were all from the Great Devon Limestone at Dart- 

 ington, near Totnes, and were obtained from a spot in the Pit-Park 

 Quarry, where the dolomitic rock, instead of being hard and crys- 

 talline, is friable and almost sandy. The Stromatoporidae appear 

 to have grown in the position in which they are foiind. They can 

 be traced for a few yards from the friable portion of the rock, but 

 gradually become merged in the crystalline rock ; and then their in- 

 ternal structure is obliterated. The author noticed the various 

 Corals, Crinoids, and Brachiopods which occur associated with the 

 Stromatoporidae. The author regarded the Stromatoporidae as a 

 somewhat heterogeneous mixture of organisms, but did not believe 

 that they were, as had been asserted, originally siliceous. Some 

 seem clearly to be of a structure like that of the Milleporidfe. With 

 regard to Caunopora placenta (Lonsd.) the author quoted Prof. 

 Phillips's remarks as to the chai'acters of the tubes traversing its 

 mass. He had observed in sections from near Teignmouth, that the 

 axis of the tube is lamelliferous, giving some appearance of a 

 columella. 



Prof. DuNCAN^ expressed his belief that many different forms were 

 united under the one head oi Stromatopom , and that the confusion was 

 often due to the mode of mineralization. He called attention to a 

 Smiihia exhibited, which, by destructive mineralization, had as- 

 sumed a deceptive resemblance to Stromatopora. He thought this 

 had been the case in some of Mr. Lonsdale's specimens. The tubules 

 in the laminae of Stromatopora certainly had much resemblance 

 to the tubules of Millepora. Some of the specimens exhibited 

 seemed to have openings like calicos ; as they opened into the ccenen- 

 chyma, they could not be corals. The cross tubules excluded them 

 from Polyzoa. They showed no true supplemental skeleton, or 



