on the Fossils of the older Deposits in the Rhenish Provinces. 31 1 



the Meandrinee and the Caryophyllaee, form at the present day the coral reefs and 

 islands of intertropical oceans*. Among the Strombodes, a genus consisting 

 but of few species, the S. vermicularis of Lonsdale {Cyathophyllum of Goldfuss), 

 is common to the two older systems. Caninia-f, a genus containing few species, 

 is at present peculiar to the Carboniferous system. The Catenipora (with a single 

 exception, which is even doubtful) characterize the lowest system in Russia, in 

 Scandinavia, on the banks of the Rhine, and in England, as well as in North 

 America: the Syringoporoe, on the other hand, are pretty equally disseminated ; 

 two species are common to the Silurian and Devonian systems, and one, the /S. 

 reticulata, Goldf,, common to Europe and America, is found in all the systems. In 

 Russia this genus particularly characterizes the Carboniferous period. 



The Favosites, including the Calamopora of M. Goldfuss, are not less important 

 than the Cyathophylla, although the number of species be less : sixteen are distri- 

 buted in the Silurian beds in England, in Germany, upon the banks of the Rhine, in 

 Scandinavia, Esthonia, and Ingria, or the district to the south of St. Petersburg ; 

 as well as in North America in almost all those places where the oldest deposits 

 are developed, that is, throughout an extent of nearly 1400 miles from east to west, 

 from the Alleghany chain to Engineer Cantonment upon the Missouri, and of 2400 

 miles from north to south, or from the shores of the Arctic Ocean and the great lakes 

 to the very centre of Alabama. Of the sixteen species, the six most abundant over 

 these immense surfaces, i. e. the Favosites or Calamopora alveolaris, Gothlandica, 

 polymorpha, Spongites, basaltica, and fibrosa (of which one, the F. Gothlandica, 

 occurs in New Holland), continue to be found in the Devonian system, in which 

 they are not less constant in England, in the north of France, in Belgium, in the 

 Eifel, upon the banks of the Rhine, and in Russia. A single species {F. infundibu- 

 lifera) appears to be peculiar to that system, and seven are peculiar to the Carbo- 

 niferous period. 



The AuloporcB are plentiful in the Silurian and Devonian beds, which they do not 

 go beyond ; and of five species four are common to these two systems ; and lastly, 

 the Alveolites and the Favosites, genera very much reduced according to the latest 

 works, are represented in the three systems. 



When taken collectively, the Polyparia are nearly similarly developed in the 

 Silurian and Devonian systems, and thirty-six species are common to them. This, 

 amounting to about a third of the species in each, is much more considerable than 

 for any other class ; for the Brachiopoda, which, next to the Polyparia, contain the 

 greatest number of species common to both beds, have only one-seventh. In the 



* The CaryophyllcBCB, the Astrece, and the Strombodes are but of slight importance in these ancient 

 beds, when the view in which we regard Cyathophyllum is taken, 

 f Michelin, Supp, Diet, des Sc. Nat. tome ii. 



2 s2 



