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XIX. — On a Silurian Scorpion and some additional Eurypterid Remains from the 

 Pentland Hills. By Malcolm Laurie, B.A., D.Sc. (Plates I.-V.) 



(Read 6th June 1898.) 



In 1892 I communicated to this Society an account of a collection of Eurypterids 

 from the Upper Silurian rocks of the Pentland Hills, in which I described new species 

 and a new genus. Since that time I have had the opportunity of examining two other 

 collections from the same locality. One of these was formed with the aid of a grant 

 from the British Association. The fossiliferous bed — for these remains occur in a single 

 thin bed of rock — was laid bare, and a considerable amount of it removed and split up. 

 In this latter work I was fortunate to get the assistance of Mr John Henderson, the 

 original discoverer of the locality, and I am glad to have this opportunity of recording 

 my indebtedness to him. A fair number of specimens was thus procured, which not 

 only threw considerable light on the structure of some of the already described forms, but 

 gave evidence of some species as yet undescribed. More important than this collection, 

 however, was the one formed by the late Mr Hardie of Bavelaw Castle, who had for 

 many years collected among the Pentland Silurians. His collection was, on his death, 

 acquired by the Edinburgh Museum of Science and Art, and Dr Traquair kindly put the 

 collection in my hands for examination. From the size of the collection I expected 

 some new and interesting results, and have been far from being disappointed. Seven 

 new species of Eurypterids have come to light and one Scorpion. These, and the new 

 facts about the already described species, form the subject of this paper. Some frag- 

 ments of Ceratiocaris have also been found, but they do not seem to me sufficient to 

 determine the species. 



The horizon of the beds is Wenlock, so far as can be ascertained from the other 

 fossils contained in it, and from the very scanty fauna of the neighbouring rocks. I 

 had come to this conclusion from my own investigations, and am glad to find that the 

 position assigned to it in the forthcoming memoir of the Geological Survey corresponds 

 to my own idea on the subject. 



The discovery of so many forms (10 in all) puts this locality far ahead of any other for 

 Eurypterids. The total number hitherto described from the Silurian of Great Britain, 

 apart from this deposit, is about 16. The only deposit approaching this for the richness of 

 its Eurypterid fauna is the Water Lime in America, from which about 1 5 species have been 

 described. Some five or six of these, however, are of very doubtful specific rank, being 

 based either on small fragments or on slight differences in proportion. The latter is for 

 Palaeozoic fossils, very unsatisfactory when one considers how much compression and 

 distortion they have undergone. The reason for the extraordinary abundance of these 



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