CHAPTER VI 



LYCOPODIALES — continued 



Ulodendron and Halonia ; Fructifications of 

 Lepidodendreae ; Bothrodendron 



I. Ulodendron and Halonia. — In the last chapter we 

 described the morphology of the stem and leaf of the 

 Lepidodendreae ; we have now to consider their organs 

 of reproduction. Before going on to the cones, some- 

 thing must be said as to two forms of Lepidodendroid 

 stem (commonly regarded as bearing the fructifications) 

 which differ so conspicuously from the ordinary type 

 that they were long described as belonging to distinct 

 genera, to which the names Ulodendron and Halonia 

 were given. The genus Ulodendron is still kept up for 

 certain species by M. Zeiller. 



The Ulodendroid form of stem is often of large size, 

 attaining in some cases a diameter of about a foot, and 

 is sometimes dichotomously branched. The general 

 surface bears the ordinary markings of the Lepidoden- 

 dreae ; where the leaf-bases are perfect they present, 

 however, in some cases, according to Mr. Kidston, the 

 characters of a Sigillaria, and so do not come under our 

 immediate subject, but in other specimens the superficial 

 characters are clearly those of a Lepidodendron (see 



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