1 50 Mr. Tate on the Berivichshire Mountain Limedone Fauna. 



is probable tliat Annelids are also entombed in some of the Ber- 

 wickshire beds, as both Annelids and Grraptolites have been 

 discovered, in other jjarts of the range, at Grierston and Thornie- 

 lee on the Tweed in Selkirkshire. 



II. — The Devonian or Old Eed Sandstone formation occupies a 

 considerable area in the central and south-western parts of Ber- 

 "udckshire. There is a fine section of it on the north side of the 

 Lammermuirs, from Siccar Point to the mouth of the Pees ; the 

 conglomerate is seen overlying unconformably the Silurian or 

 Cambrian strata. In Northumberland we find it in Eoddam 

 Dean on the flanks of the Che^dot Porphyry, where it contains 

 rolled pebbles and blocks of this Porphyry, evidencing that the 

 Cheviots had been protruded previously to the deposition of the 

 Old Red conglomerate. There is no physical break in Berwick- 

 shire between the Old Eed Sandstone and the Carboniferous form- 

 ation ; but the limits of the former are nearly marked by the 

 occurrence, near to the Pees mouth, of Holoptijcliius nohiUssimus 

 and Pterichthys major, which are fish characteristic of the upper 

 beds of the Old Red Sandstone. 



III. — The Carboniferous formation occupies nearly the whole of 

 Northumberland, and a considerable area of the south of Berwick 

 shire, with a small patch or two in the northern part of that county. 

 Pour groups are distinguishable ; commencing with the uppermost 

 we have : 1— The Coal Measures ; 2— The MiUstone Grit ; 3— The 

 Mountain Limestone ; 4 — The Tuedian Group. 



1 — The Coal Measures are a series of alternating strata of sand- 

 stones, shales, ironstone, and coal ; with an abimdance of remains 

 of land plants, and, in a few beds, of Pish and fresh- water 

 Mollusks, {Anthrocosia King), allied to the Unio of our rivers. 

 Lacustrine conditions are generally indicated. 



The term "Coal Measures" usually applied to this group is 

 objectionable, because workable beds of coal are contained in other 

 groups, though not in such abimdance and excellence of quality as 

 in this. These Coal Measures constitute the Newcastle coal field, 

 and occupy the triangular area in Northumberland which lies east- 

 ward of a line drawn from the mouth of the Coquet to Wylam on 

 the Tyne. They do not extend into Berwickshire. 



2 — The Millstone Grit consists of coarse gritty and conglomerate 

 beds interstratified with sandstones and with thin beds of coal. It 

 lies at the base of the Coal Measures, and forms a narrow zone 

 running from the mouth of the Aln nearly parallel with these 

 Coal Measures. It contains remains of plants and Annelids. 

 Grains of Protoxide of Iron and Garnets are found occasionally 

 in the gritty sandstones. 



3 — The Mountain Limestone is a more complex group than the 

 Coal Measures ; it has similar alternations of sandstone, shale, iron 

 stone and coal, and contains similar fossil plants ; but we have 

 indications of a new condition ; for intercalated with these strata, are 

 several limestones and calcareous shales, in which marine remains 

 are abundant. The most characteristic fossils are Brachiopods, 

 especially Producti, and hence some of these beds have been called 



