54 



ERA OF THE TRIAS AND OOLITE. 



REPTILES ABUNDANT. FIRST TRACES OF BIRDS AND 



MAMMALIA. 



GEOLOGISTS now apply the term Secondary Formation (once 

 of wider application) to those intervening between the end of 

 the Permian or close of what they call the Palaeozoic Period, 

 and the termination of the Chalk Series, afterwards to be 

 described, at which place there is another and almost total 

 change of specific forms. The first of these formations is 

 called with us the Upper New Red Sandstone ; it consists, in 

 England, of only a group of strata of that kind, surmounted 

 by some variegated marls. But on the Continent, below a 

 stratum equivalent to these marls, there is one of limestone, 

 bearing the name of the Muschelkalk, and full of shells. The 

 system is there called Trias, on account of its thus consisting 

 of a triple group of strata. 



TRIAS. 



THE organic relics of this system are most abundant in the 

 Muschelkalk. There we are presented with a great number 

 of crinoids and shells, all differing in specific character from 

 their predecessors of the same orders. The crinoid called, 

 from its elegant lily-like shape, Encrinites Moniliformis, is a 

 conspicuous fossil. The brachiopods, here almost extinct, are 



