DEVONIAN AND OLD l!Kl> SANDSTONK SY.-TKM 



species df ,<{)infer (S. macroptfrns, >'. i-nltriju'intns, etc.) with 

 Chonetes sarcinulata, Homalonotns yiyas, and Ctenocrinux. 



Tin- Middle Devonian of the Upper Harx is largely argillaceous, 

 consisting in the lower part of interbedded shales and argillaceous 

 limestones with Calceola sandalina and other fossils. Above these 

 are sheets of diabase and a thin band of Strinyocephaius limestone 

 succeeded by the Goslar shales which, however, seem to lie partly <>f 

 Upper Devonian age. In the Lower Harz the Givetian is letter 

 represented by the limestone of Elbingerode with its associated beds 

 of ironstone and volcanic tuft'; this limestone has yielded the 

 Goniatites Mteneceras terebratum and Tornoceras dnctnu,. 



The Upper Devonian as developed in the Western Harz com- 

 prises the following beds : 



"Cyrpidina shales " with Entomis scrrato-striata. 

 Green limestone with Clymenias and Pha-cojts brevis. 

 Black limestone of Altenau with Goniatites retrorsus. 

 Shales with thin layers of black chert. 



Near Clausthal, however, two hills called the Iberg ami the 

 Winterberg are of much interest, for they are parts of an isolated 

 mass of Upper Devonian limestone, rising through the surrounding 

 Carboniferous shales and greywackes, which are folded and crumpled 

 round its sides. This Iberg limestone is believed to be 1300 feet 

 thick, and has more resemblance to a coral reef than any such lim-- 

 stone mass in England or France. It Is a massive limestone com- 

 l>nM>d mainly of the remains of corals and shells, including several 

 species of Acervularia, the Brachiopods Khynch. cuboides, B. 

 pugnus, Orthis striatula, and Spirifer bifidus, and the Cephalopoda 

 Gephyroceras intumescens and G. IVurmii, with many species of 

 ( ;,i-tnjpoda. 



Devonian rocks crop out again to the south in Thuringia, but 

 are much broken and flexured, so that there is no continuous 

 succession. 



f>. Bohemia 



The Silurian Series recorded on p. 184 is succeeded by limestones 

 which must be referred to the Devonian System, in spite of their 

 containing a mixture of Silurian and Devonian fossils which caused 

 them to be regarded for many years as a part of the Silurian. These 

 beds form the stages F 2 , G, and H of Barrande (see Fig. 45, p. 143), 

 and exhibit the following descending succession : 



