316 DR JOHN S. FLETT 



the west side of Noss Sound a small volcanic neck, described by Peach and Horne (29), 

 occurs, with a thin bed of ash. Faulting also is visible here, and the beds are often 

 steeply inclined. In Noss the easterly dip again prevails, and in the great cliff on the 

 east side of this island a fine section of thin flaggy sandstone and grey shales is 

 exposed, exceedingly well stratified, and resembling closely many of the cliff features of 

 Orkney and Caithness. 



In view of the persistent easterly dip, often at fairly high angles, the whole thick- 

 ness of this series must be several thousand feet ; but the evidence of faulting along the 

 shores of the Sounds is sufficient to render exact estimates impossible. The fish beds 

 in Cullingsburgh Voe are rather above the middle of the Bressay Sandstones. The 

 fossils occur in a thin-bedded, flaggy, grey micaceous sandstone, and the plates are 

 black in colour and well preserved. With them thin black impressions of plants are 

 exceedingly common. The strata were evidently laid down in shallow water, close to 

 land ; and the general facies of the rocks and of the fauna is in harmony with the 

 supposition that they were fresh-water deposits. 



Fossiliferous bands must occur in Bressay besides that in which our excavations 

 were made, as we found a fish fragment in a beach stone on the east side of Cullingsburgh 

 Voe, and another in a loose rock to the west of the houses of Cullingsburgh. Professor 

 Heddle (20), (10) tells us that he saw " specimens of small fishes, apparently acanthoides, 

 embedded in a fine-grained muddy sandstone ; they were stated to occur in a quarry north 

 of Gardie, in Bressay." There is no reason to doubt this record ; but, unfortunately, the 

 fishes can no longer be traced (if they were preserved). I made a careful search in all 

 the quarries near Gardie, but could see no remains of fossil fishes. It is clear that the 

 Shetland Old Red Sandstone is by no means so barren as has hitherto been supposed ; 

 but to obtain good fossils, great skill and patience, with some measure of luck, will be 

 required. 



The Fauna op the Bressay Sandstones. 



The fish-remains obtained in these beds have been determined by Dr Traquair to 

 belong to Asterolepis (sp.) and Holonema (sp. nov.) ; possibly there are also fragments 

 which may be referred to a species of Holoptychius. Of these genera, the first is 

 typically Upper Old Red ; it occurs also in beds assigned to that series at Nairn. 

 Holonema is a genus founded by Newberry (26) for remains from the Chemung beds 

 (Upper Devonian) of North America. Holoptychius is a very characteristic Upper Old 

 Red genus. So far, then, the evidence of the fish fauna points clearly to the Shetland 

 beds belonging to the Upper part of the Old Red system. It is not, however, absolutely 

 satisfactory when closely examined. The Holonema is a new species ; the Asterolepis 

 also is probably new, though as yet not definitely named ; and caution is necessary in 

 classifying Old Red faunas in such cases. As an example of this we may quote the 

 typical Lower Old Red genus Cejihalaspis, which occurs in the Middle Old Red of 



