CARBONIFEROUS PERIOD. 



335 



Ettingshausen, are over a foot long, and are as closely crowded about the 

 branches as in any modern Pine. See also the trees on the frontispiece, above 



Fig. 563. 



Fig. 567. 



Halonia pulchella. 



Extremity of a branch of Lepidodendron, with the 

 leaves attached. 



referred to. Fig. 564, part of the surface of the Lepidodendron obovatum Stern- 

 berg, a common species both in the United States and Europe. Fig. 565, L. cly- 

 peatnm. The cones (Lepidostrobus) found in the same rocks with the Lepidodendra 

 are regarded as their fruit. They have some resemblance to the cones of Pines. 

 Fig. 567 represents a portion of the stem of Halonia 2Jtdchella Lsqx., a plant 

 similar to Lepidodendron, from the Coal measures of Arkansas. 



2. Sigittaria tribe. — The iSigillarice (figs. 568, 569) are most abundant 

 in the Lower Coal measures, and appear to have taken a great part 

 in the formation of the Coal. They are supposed to have grown 

 over the great marshes of the era in which the Coal vegetation 



