186 II. S. WILLIAMS — THE CUBOIDES ZONE AND ITS FAUNA. 



Iii the Hi Mian and similar sections it is the Cuboides Kalke and Mergel or 

 merely Ouboides Schichten of Kayser. These again are followed by shales 

 and sandstones and occasional impure limestone. 



In the transition from the purer Stringoeephalus limestone to the coarser 



upper Devonian sandstones, the first stage is that of the argillaceous lime- 

 stone (or MergeV), containing the Cuboides fauna; second, a fine-grained, 

 often black and occasionally concretionary shale, containing Gonial iff* very 

 generally, and frequently having few fossils and those small, among which 

 is the Cardiola retrostriata. Above these are the Cypridinen shales and 

 sandstones and occasional limestones with the later Devonian faunas. 



The Cuboides Fauna. 



The principal fossils of the Cuboides Schichten, according to Kayser,* are — 



Rhynchonella cuboides, Sowerby. 

 Spirifer Verneuili, Murchison. 

 Receptaculites N&ptuni, Defrauce. 



Besides these, as conspicuous fossils in the fauna, Kayser names — 



Spirifer euryglosus, Schnur. 

 Sj,irifer nudus, Sowerby. 

 Rhynchonella pugnus, Mart. 

 Rhynchonella acuminata, Mart. 

 Produetus subaculeatus, Murch. 

 Athyris concentrica, v. Buch. 

 Atrypa reticularis, Lin. 

 Pentamerus galeatus, Dal in. 

 Orthis eijelensis, de Vera. 

 Orthis striatula, Schloth. 

 Melocrinus hieroglyphicus, ( roldf. 

 Phillvpsaatrcea verneuili, Edw. <V II. 

 Acervul'irin pentagona, Edw. & II. 



This precise horizon, with the general sequence from the middle Devonian 

 Limestone to the upper or Condrozien sandstone, was traced by Kayser from 

 Belgium through these western German sections to the Harz sections, and 

 Poland, Russia, Petschora land, the Urals, Persia, and China. 



I n each well-exhibited Bection there is 



I. The rich middle Devonian fauna : brachiopods, corals, gasteropods, 

 laraellibranchs in abundant variety; trilobites, crinoids, and cephalopods 

 in lesser aumbi 



...I, der Gegend \ .mi \:i. hen, I, <-., p. sit, 



