BUFFALO SOCIETY OF NATURAL SCIENCES 131 



dates could lead to any other conclusion but that the eurypterids 

 dwelt in the Wenlock sea? It is just because such a conclusion in 

 reality is entirely unjustifiable that I was led to state at the beginning 

 of this paragraph that the eurypterid occurrence in the Wenlock is 

 the most significant one in the British Isles when its interpretational 

 value is taken into account. 



Wenlock of the Pentland Hills. The Pentland Hills are 

 formed from a series of the folded pre-Devonic beds and are completely 

 surrounded by the various sub-divisions of the Old Red sandstone and 

 by the igneous rocks. The Siluric rocks are exposed in four small 

 isolated patches in these hills, and yet in spite of the small size of the 

 outcrops and their isolation they have yielded more species of euryp- 

 terids than any other single formation in the world, with the excep- 

 tion of the Bertie waterlime, though there is this marked difference 

 between the two faunas: whereas the Bertie fauna contains the most 

 perfectly preserved individuals that have yet been recorded from 

 any locality, with the exception of those from Oesel, the Pentland 

 Hills fauna, on the other hand, is made up, for the most part, of 

 fragmentary individuals. • 



The most important of these four inliers is that extending from 

 the head of Lyne water to the head of North Esk River, a distance 

 of about three miles. Although this inlier is the largest of the four 

 it covers an area of only about two to three square miles. A number 

 of excellent sections have been opened up by the North Esk and its 

 various tributaries. The river itself cuts across the outcrop nearly 

 at right angles, and since the beds here as in the other inliers are 

 strongly folded, standing on end with the strike northeast-southwest, 

 a considerable range in age is shown in the section, the lower beds 

 appearing to the east, in the North Esk section where the Wenlock, 

 Ludlow and a portion of the Lanarkian (Downtonian) are exposed, 

 while to the west the Lyne water cuts through the passage beds or 

 Downtonian. Of the numerous sections thus exposed the one which 

 has now become most famous on account of the large eurypterid fauna 

 discovered there by Hardie and Malcolm Laurie is that on the Gutter- 

 ford Burn, a small tributary of the North Esk. (See map, fig. 12.) 

 On the east bank of the burn, about a half a mile up from the North 

 Esk Reservoir the strata consist of " flaggy micaceous greywackes" 

 dipping at about 80 degrees to the southeast. Peach and Home give 

 a list of the fossils which they state come "from this band" (215, 

 593), but one may question the accuracy of this statement when com- 



