( 151 ) 



X. — On Some Eurypterid Remains from the Upper Silurian Rocks of the Pentland 

 Hills. By Malcolm Laurie, B.Sc, F.L.S. (With Three Plates.) 



(Read 21st December 1891.) 



The Upper Silurian rocks of the Gutterford Burn, in the Pentland Hills, have for 

 some time been known to contain Eurypterid remains,* but the fossils procured from these 

 beds — chiefly owing to the exertions of Mr Hardy of Bavelaw Castle, and Mr Henderson, 

 late Curator of the Phrenological Museum — have never been submitted to a thorough 

 examination. When, therefore, by the kind permission of Sir E. Murdoch Smith, 

 Director, and Dr E. H. Traquair, Keeper of the Natural History Collection in the 

 Edinburgh Museum, I was given an opportunity of examining Mr Henderson's collec- 

 tion, which was acquired by the Museum some years since, I entered upon the work 

 with the expectation of finding some new and interesting forms which would repay 

 description. My expectations in this respect have been more than fulfilled, as the collec- 

 tion has yielded five undoubtedly new species, one of which I have made the type of a 

 new genus. If to these one adds at least two other new species which are in the collec- 

 tion of Mr Hardy of Bavelaw, and which I hope to have the pleasure of examining and 

 describing at some future time, one is justified, I think, in saying that the Gutterford 

 Burn is unequalled among Eurypterid localities with regard to the variety of forms it 

 has yielded. Unfortunately the bed which has yielded these specimens is limited in 

 extent, and further work on it would entail quarrying operations on a somewhat exten- 

 sive scale. ' -• 



The rock in which the Eurypterids are preserved is an irregularly fissile fine-grained 

 sandstone, containing a considerable amount of carbonaceous matter distributed in thin 

 layers. The only other recognisable fossil which occurs in the rock is the so-called 

 Dictyocaris Eamsayi, which occurs in considerable abundance. 



One point which has struck me in working at this collection is the large size of the 

 eyes in most of the forms. The reason of this must be sought in the conditions under 

 which they lived, and a comparison with recent forms would suggest deep water, but 

 there is not sufficient evidence to make this more than a conjecture. 



I would like to take this opportunity of expressing my thanks to Dr Traquair, both 

 for the permission to examine this interesting collection, and for the assistance he has 

 given me throughout the work. 



Genus Stylonurus (H. Woodw.). 



This genus, which is characterised by " the peculiar form of the carapace, the great 



length of the telson or terminal joint, and the substitution of two pairs of long, slender, 



* Henderson, Trans. Edin. Geol. Soc, vol. iii. 

 VOL. XXXVII. PART I. (NO. 10). 2 A 



