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XXXIII. — Supplementary Report on Fossil Fishes collected by the Geological Survey 

 of Scotland in the Upper Silurian Rocks of Scotland,. By Ramsay H. Traquair, 

 M.D., LL.D., F.R.S., Keeper of the Natural History Collections in the Royal 

 Scottish Museum, Edinburgh. (With Three Plates.) 



(Read July 5, 1901. Given in for publication November 29, 1904. Issued separately January 26, 1905.) 



Since the publication of my "Report" in December 1899, Mr Tait, fossil collector 

 to the Geological Survey of Scotland, has been successful in adding a number of 

 specimens of great interest to the valuable series of Scottish Silurian Fishes which 

 supplied the material for that memoir, and with the permission of the Director of the 

 Survey, to whom my best thanks are due, I propose to give descriptions of them in the 

 following Supplement. The search for these remarkable fishes has likewise been taken 

 up by private collectors, and I have therefore pleasure in acknowledging my indebted- 

 ness to Messrs J. Young, of Lesmahagow, P. Macnair, of Glasgow, A. Whyte and 

 F. White, of Muirkirk, and D. Nimmo, of Hamilton, for kindly submitting to me the 

 material resulting from their own work in this field. 



The present communication is concerned only with the recording of additional 

 facts, further discussion of the theoretical points suggested by the study of these 

 ancient fishes being reserved for another paper. 



Historical Note. 



The first finder of these fish-remains in the Silurian rocks of the South of Scotland 

 seems to have been the late Dr Slimon, the well-known collector of the fossil Crustacea 

 and Merostomata of the Lesmahagow district. It was from Mr Macnair that I 

 received information that the Slimon Collection, now in the possession of Miss Slimon, 

 contained examples of Thelodus and Birkenia from the "Ludlow" beds of Logan 

 Water, and I can confirm the fact from personal examination of the specimens. These 

 are, however, imperfect ; and as they have no labels, we have no evidence as to whether 

 or not Dr Slimon recognised them as fish-remains. 



To Mr Macnair I am also indebted for the loan of a microscopic slide of scales of 

 Tlielodus Scoticus, apparently from Logan Water, which he found in the collection of 

 fossils formed by the late Dr John Young, and now in the Glasgow Corporation's 

 Museum at Kelvingrove. In bhis slide the minute structure of the simple dentine 

 substance of which the scales are composed is very clearly shown. 



In my previous memoir I mentioned the fact that Mr James Young had found a 

 fish in the Logan Water beds before the locality had been visited by the collectors of 

 TRANS. ROY. SOC. EDIN., VOL. XL. PART IV. (NO. 33). 6 p 



