366 THE CANADIAN NATURALIST. [June 



manner, and, as Mr. Brown has shown, in some species at least, 

 give off conical tap-roots from their underside. 



In all the Stigniariae exhibiting structure which I have 

 examined, the axis shows only scalariform vessels. Corda, how- 

 ever, figures a species with wood-cells, or vessels with numerous 

 pores, quite like those found in the stems of Sigillaria proper ; 

 and, as Hooker has pointed out, the arrangement of the tissues in 

 Stigmaria is similar to that in Sigillaria. After making due 

 allowance for differences of preservation, I have been able to 

 recognize eleven species or forms of Stigmaria in Nova Scotia, 

 corresponding, as I believe, to as many species of Sigillaria.* At 

 the Joggins, Stigmariae are more abundant than any other fossil 

 plants. This arises from their preservation in the numerous 

 fossil soils or Stigmaria underclays. Their bark, and mineral 

 charcoal derived from their axes, also abound throughout the 

 thickness of the coal beds, indicating the continued growth of 

 Sigillaria in the accumulation of the coal. 



Our knowledge of the fructification of Sigillaria is as yet of a 

 very uncertain character. I am aware that Goldenberg has 

 assigned to these plants leafy strobiles containing spore-capsules : 

 but I do not think the evidence which he adduces conclusive as 

 to their connexion with Sigillaria ; and the organs themselves are 

 so precisely similar to the stobiles of Lepidophloios, that I 

 suspect they must belong to that or some allied genus. The 

 leaves, also, with which they are associated in one of Goldenberg's 

 figures, seem more like those of Lepidophloios than those of 

 Sigillaria. If, however, these are really the organs of fructifica- 

 tion of any species of Sigillaria, I think it will be found that we 

 have included in this genus, as in the old genus Calamites, two 

 distinct groups of plants, one cryptogamus, and the other phaeno- 

 gamous, or else that male strobiles bearing pollen have been mis- 

 taken for spore-bearing organs. 



I cannot pretend that I have found the fruit of Sigillaria 

 attached to the parent stem ; but I think that a reasonable 

 probability can be established that some at least of the fruits 

 included, somewhat vaguely, by authors under the names of Tri- 

 gonocarpum and Rhabdocarpus, were really fruits of Sigillaria. 

 These fruits are excessively abundant and of many species, and 

 they occur not only in the sandstones, but in the fine shales and 



* See Paper on Accumulation of Coal, Journ. Geol. Soc, vol. xxii. 



