222 NATURAL HISTORY 



sandstone whioh is associated with the coal, and also in 

 the slate clay with which it alternates, there frequently 

 occur remains of common and of arborescent ferns, gi- 

 gantic reeds, palms, and leaves of a tree which resembles 

 the casuarina, and which was long considered as an equise- 

 tum. In the limestone, slate clay, &c. of the coal fields 

 in this country, many petrifactions occur, such as ortho- 

 ceratites, ammonites, nautilites, serjpulites, patellites, he- 

 licites, turbites, buccinites, trochites, mytulites, cardites, 

 anomites, pectinites, echinites, entrochites, and millepo- 

 rites. Bones and teeth of fishes are said to have been 

 also found in the coal formation. 



II. First Fleet z Limestone. 



This limestone rests immediately on the first sandstone 

 formation. It is divided into the following members : 

 1. Alpine limestone. 2. Bituminous marl slate. 3. Zech- 

 stein. 4. The coal subordinate to the formation in ge- 

 neral. 



1. Alpine Limestone.* 



This is the most highly crystallized limestone of the 

 series. It is principally characterized by the ammonites 

 and lenticulites it contains. In it we also meet with single 

 coralliolites, encrinites, terebratulites, ostracites, bucci- 

 nites, chamites, echinites, belemnites, and gryphites. 



'. 2. Bituminous Marl Slate. 



This remarkable limestone is very widely distributed, 

 and often contains abundance of petrified fishes, which 



* This limestone appears to agree in many characters with the 

 mountain or matalliferous limestone of England, and like that rock to 

 rest sometimes upon old red sandstone, and sometimes upon grey- 

 wacke. If is very intimately related to both these great formations^ 



