2S2 MR. E. WETHERED ON THE OCCURRENCE OF 



interpretation of tul3nlar structure, though these mystifying appear- 

 ances seem more common in serpentine and chalcedony than in cal- 

 cite. In the bodies depicted, the wall, the irregularity, and the 

 manner in which the tubes curve round each other are in favour of 

 their being organic. 



Prof. Rupert Jones thought that these forms were not due to 

 mineral, but to organic laws. The surrounding enallostegian lines 

 looked like tubuli (he was not prepared to ignore those of Eozoon), 

 quite analogous to those mentioned by the Author, and })erhap8 to 

 those of the small knots of Serpulce in the Chalk ; but whether the 

 latter are continuous or not, is doubtful. As to difference in the 

 size of the tubules there was not much in that. He referred to the 

 views of Schaf hautl, who had given distinct names to oolitic granules 

 from the Alps of South Eavaria. He suggested that some markings 

 in flint had been due to thread-like Poraminifera in the chalk. 

 He congratulated the Author on his successful research ; also on 

 his not claiming that all oolitic granules were derived from this one 

 source. 



Dr. Evans, while disclaiming an j^ special knowledge of the subject, 

 suggested that the appearances might be interpreted on the supposition 

 of an organism boring into a comparatively hard substance. He also 

 referred to other difficulties in the way of the Author's interpreta- 

 tion, though there could be little doubt as to the organic nature of 

 the structures. 



Dr. Hinde, who had seen most of the known species of Girvanella, 

 spoke of the wide distribution of these organisms. Dr. Bornemann 

 had found them forming a bed of rock of Cambrian age in Sardinia, 

 and he referred them to calcareous algse ; Prof. Mcholson originally 

 noted their occurrence in the Ordovician rocks of Ayrshire ; and he 

 (the speaker) had found them in limestones of similar age in the 

 Province of Quebec. They are undoubtedly organic ; the tubes have 

 definite imperforate walls of granular calcite, distinct both from the 

 matrix and from the calcite infilling them, and they could not therefore 

 be mere borings. The ' Challenger ' Poraminifera, with which they 

 were compared by Dr. Brady, are considerably larger and are also 

 built up of arenaceous grains. Girvanella had been erroneously 

 described as a Calcisponge, and compared to knots of Seiyulce, but 

 we can hardly conceive that worms inhabited such small tubes. 



Dr. Hicks referred to the walls of borings, in the Cambrian and 

 Silurian rocks, giving an appearance of being distinct from having 

 been lined with calcite. 



Prof. BoNNEY felt sure the specimens had no place in the mineral 

 kingdom, and organic fragments were common in them, for there 

 had been no great degree of molecular change in these beds. What 

 organism the Girvanella might be he would not venture to sa5\ 



Prof. Jtjdd referred to the oolitic grains from the coral-reefs of 

 the Bahamas, which had been described by De la Beche and Sorby. 

 The study of these recent oolitic grains might be expected to lead to 

 important results. He had found in them structures similar to 

 those described by Mr. Wethcred, but the structures are finer even 



