TOAL FORMATION. 



41 



tached, but entire and 



from the middle nervurc, apd 



great number of other genera 



*he nervures arise very obliquely 

 s frequently divide ; arid a 

 on the form of their leaJleu 



Fig. 33.SphcEnopieris Hccni^gh^usi. Fig. 39. Neuropteris Loshii. 



and the arrangement of their nervures. We also find various other 

 plants, the families of which are uncertain, such as the Spheno- 

 nhy ltif.es (/#. 40), dnnula'ria, &c. (fig. 41), which are very 

 abundant in certain localities. 



Fig. 40. Spheno'phyllum 

 den ta turn. 



Fig. 41. Annula'ria brevifolia. 



11. True equisita appear to have existed in the coal-measures ; 

 but we are also led to place in the same family certain stems, 

 grooved lengthwise, with joints at intervals from which branches 

 sometimes spring (figs. 42, 43). These stems, called ca'lamites, 



10. Name seme of the genera of fossil plants found in coal-beds. 



4* 



