404 Dr. T. J. Jehu — Tlie Highland Border Series. 



Other Obscure Forms. 

 Among these are what may possibly be pieces of skin of an Arthropod 



alUed to Eurypterus. An obscure Graptolite referred to later. 

 The following remains were found in cherts on the hill-top just above the 



road where the old aqueduct crosses the valley, opposite the Drum of 



Clashmore : — 



1. Flattened chetse of annelids preserved in iron pyrites. 



2. Casts from which iron pyrites nodules have sprung out and which 



look very like the casts of Eadiolaria. 



The fossils obtained from this district were on exhibition at Dundee, 

 at the British Association meetings, 1912, and they were examined by 

 Dr. Ami, F.R.S. Can., of Ottawa. In a letter sent subsequently to 

 Dr. Home, he stated that the fossils closely resemble those obtained 

 from Upper Cambrian beds belonging to the Quebec Group. His opinion 

 was based partly on the Brachiopods and partly on the presence of an 

 obscurely preserved Graptolite resembling Reiiolites ensiformis, Hall, 

 a type characteristic of the Sillery Sandstones of the Quebec Group 

 (Upper Cambrian). The great interest attaching to the identification 

 of a Graptolite from the Highland Border rocks was at once 

 recognized, and the specimen was sent to Miss G. L. Elles, Cambridge, 

 for examination. She has kindly supplied the following description: — 



Three thecal 



:^<'' 



iree thecal 'Z--%'^>-<X\S.^.- 'jx- 

 apertures. 1 — \^|XJ'') Y- s 



Reticula. 



Part of 

 Thecal ,T^ clathria. 



aperture. ^7Yii 



/•* 



Reticula. 



X 8. 



Fig. 2. — Sketch of an obscure Graptolite from Aberfoyle. 



"The specimen appears to me to show traces of thecse, with a fairly well- 

 developed reticula and clathria. It would appear to belong to Retiolitidse. 

 The strands belonging to the clathria are the median longitudinal strand 

 and several lateral fragments seen on its left side ; those on the right are 

 more obscure. The reticula is of much the same nature as that of 

 Plegmatograptus selula, but this Graptolite has no well-developed clathria. 

 Four thecal apertures are discernible, three close together on the extreme 

 left and one some little distance below them. The fact that none are seen 

 on the right is probably due to the fact that the left side of the polypary is 

 turned towards the observer, the right being turned away." — G. L. Elles. 



The evidence afforded by the fossils shows that the Highland 

 Border Series is of Lower Palseozoic age — probably Upper Cambrian 

 or Lower Ordovician. The field relations of the rocks of this series 

 to the rocks which succeed them on the north are by no means clear. 

 The working out of this problem will throw further light on the true 

 stratigraphical position of the metamorphic rocks in the Southern and 

 Central Highlands. 



I 



