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



from the lowest to the highest representatives of the Devonian. Arenaceous 

 Bhales, schists, slates, and sandstones, with some thin and more or less len- 

 ticular limestones, occupy tin- whole interval. There is, however, a progres- 

 sive change in the Faunas, which is fairly well distinguishable as coordinate 

 with the successive stages in the faunas of the Eifelian Devonian. In France 

 and Spain evidence of the Bame order of sequence is seen, but the boundaries 

 and divisions are less sharply marked. In Russia similar combinations of 

 species are recognized, bul the oscillations expressed by sedimentation are at 

 different stages as gauged by the biologic history. Still, in general, the 

 sequenceof faunas is the same. The mosl that can he said for the represen- 

 tatives of the system further east, in Persia and China, is that the associations 

 of species are closely like those of the several stages of the Devonian in 

 northern Europe. 



The Frasxien Fauna of Gosselet. 



Gosselet describes the " Calcaire et Schistes de Frasne " in Belgium, giv- 

 ing lists of fossils, in the " Es<piisse ( leologiipie," Lille, 1<S.S0, pp. !)5-97. 

 The species enumerated by him are — 



Bronteus flafo I lifer. Rhynchonella cnboides. 



Orypha us arachnoides. Camarophoria formosa. 

 Goniatites inlumeseens. " megistana. 



Spirifer nudus. Pentamerm brevirostris. 



" urii. Orthix striatula. 



" euryglosus. Produdus subaeuleabus. 



" bifid us. OyatHophyllum hexagonum. 



" vemeuili. Favosites cervicornis. 



" orbeUianus. Alveolites osquaUs. 



Spirigera concentrica. Ac milnrin goldfusn. 



Atrypa reticularis. Receptaculites neptunu 

 Rhynchonella simila vis. 



jselel notes as a Btriking fact connected with these Frasnien shales and 

 Limestones the inconstancy and irregularity of the calcareous part. Some- 

 times the limestone is at the base ; sometimes in the middle or in the upper 

 part. Cn one of the sections near Prasne the limestone forms a compact mass 

 500 to 600 metres thick, in regular beds. Easf and wesl it is represented by 

 -hales throughout. 



All through the northern part of Europe, also in Russia and the CJral 

 mountains, this Ouboides fauna i- associated with the shaly limestones ami 

 calcareous Bhales terminating the Devonian series of limestones, running up 

 into sandy Bhales, these latter often black ami bituminous, a- at Budesheira 

 and in the Dominick Bchists of Petschora land. 



