REVIEWS. 



63 



account possess but little intrinsic value, we find the fol- 

 lowing interesting notice on the Silurian rocks of the dis- 

 trict. 



The lower division of the Silurian system is recognised in the grey- 

 wacke of the environs of Priim and Daun, whilst the limestone of Scho- 

 necken and Gerolstein is, if we may judge from the fossil contents, a 

 part of the middle division of that system ; but the upper portion has not 

 yet been traced. As the roofing slates and the quartz rocks of the Hiind- 

 riicken belong to the Cambrian system, and as the coal strata of Saar- 

 briicken is deposited on these, there is a deficiency, not only of the whole 

 Silurian system of the Eifel, but also of the old red sandstone and the 

 mountain limestone ; with this proviso, however, that the limestone in the 

 neighbourhood of Stromberg, and to the N.E. of Kirn, and the fossilife- 

 rous quartzose slates of Abentheuer near Birkenfeld leave grounds for 

 supposition, that the Silurian system on the S. side of the Hiindsriicken 

 was lowered by convulsions in the line of the quartz rocks, and subse- 

 quently covered by the coal strata, and perhaps that it was again dis- 

 turbed by their formation." 



With reference to the coal formation itself, our author 

 gives the following description : 



" The stratification of the carboniferous series is generally parallel 

 with that of the slate from Metlach to Bingen, with a fall of 18°— 20° S ; 

 whilst in the southern portion of the district in question, namely from 

 Saarbriicken to Lebach, and from Miinchweiler on the Glau, to Oderfi- 

 heim, the stratification is in the same angle to the north. The only de- 

 viations from this rale occur in the neighbourhood of the porphyry and 

 trap rocks, so that the system is most complete at the greatest distance 

 from those rocks." 



" The coal series consists principally of grey schist and greyish white 

 sandstone, the former contains bands of dark grey iron stone, generally 

 only a few inches in thickness, separated from each other by many feet 

 of schist, and containing many remains of fish, amongst which are found: 

 Acantlioides Bromiii, Amhlypterus macropterus, A. ewpterygius, A. lateralis, 

 A. latus, Palaeniscus Duvernoy, P. minutus, and Figopterus lucius, of which 

 the second named is the most plentiful." 



" The beds of coal are sometimes 8 — 14 feet, but are most frequently 

 under two feet in thickness. The sandstone, grit, and iron clay of this 

 series, contain the carbonized remains of extinct plants. In the lime- 

 stone which occurs occasionally within the limits of the coal series, im- 

 pressions of plants are rare." 



