with that in many existing trees, particularly _Myrica_ and _Alnus_. It is suggested that the formation of the coralline root-tubercles is a feature consistent with the view that _Cordaites_ lived in saline marshes, a physiologically dry habitat favourable to the occurrence of mycorhiza. [Illustration: Fig. 477. A, root of _Cordaites_. B, centre of the root enlarged; _p_, periderm; _s_, space. (Kidston Coll. 1906.)] [Illustration: Fig. 478. Root (_Cordaites_?) exposed in the bed of the Vaal river. (After Mellor and Leslie.)] Reference has already been made to the habit of Cordaitean roots in the general account of the genus (figs. 468, A, 478). The specimen shown in fig. 478 may be a root of _Cordaites_ (_Noeggerathiopsis_) _Hislopi_, but nothing is known as to its structure[698]. +Reproductive Organs.+ =Cordaianthus.= Grand’Eury. We have as yet no definite knowledge of the nature of the reproductive organs of _Mesoxylon_ and _Poroxylon_, but having regard to their close resemblance in other respects to _Cordaites_, particularly in the case of _Mesoxylon_, the presumption is that some of the seeds and fertile shoots attributed to _Cordaites_ may belong to other members of the Cordaitales. Despite the abundance of _Cordaites_, or at least of material assigned to that genus, and the comparative frequency of fertile shoots in actual connexion with foliage-shoots, the practical identity of _Mesoxylon_ and _Cordaites_ leaves precludes any confident use of the latter name in a strict sense.