The occurrence of long simple or branched and sometimes capitate hairs is a common feature of Carboniferous megaspores (fig. 191, E, F, I). It is possible that these appendages served to catch the microspores, thus facilitating fertilisation. A peculiar form of megaspore has been described by Mrs Scott[437], and assigned by her to _Lepidostrobus foliaceus_, the megasporangium of which apparently contained only four spores. As shown in fig. 191, G, a large bladder-like appendage characterised by radiating veins is attached to the thick spore-coat; it is suggested that this excrescence may be compared with the “swimming” apparatus of the recent water-fern _Azolla_. The epithet swimming which it is customary to apply to the appendages of _Azolla_ megaspores would seem to be inappropriate if Campbell[438] is correct in stating that spores of _Azolla_ are incapable of floating. B. _Spencerites._ _Spencerites insignis_ (Williamson). Fig. 192. 1878. _Lepidostrobus sp_., Williamson, Phil. Trans. R. Soc., p. 340, Pl. XXII. 1880. _Lepidostrobus insignis_, Williamson, Phil. Trans. R. Soc., p. 502, Pl. _XV_. figs. 8–12. 1889. _Lepidodendron Spenceri_, Williamson, Phil. Trans. R. Soc., p. 199, Pl. VII. figs. 20–22; Pl. VIII. fig. 19. 1897. _Spencerites insignis_, Scott, Phil. Trans. p. 83, Pls. XII–XV. Another type of lycopodiaceous strobilus, differing sufficiently from _Lepidostrobus_ to deserve a special generic designation, is that originally described by Williamson[439], from the Lower Coal-Measures of Yorkshire, as a type of _Lepidostrobus_, _L. insignis_, but afterwards[440] more fully investigated and assigned to a new genus by Scott[441]. It should be pointed out that in a later publication Williamson spoke of the lycopodiaceous axis, which he suspected might belong to his _L. insignis_, as possibly worthy of recognition as a distinct generic type. [Illustration: FIG. 192. _Spencerites insignis_ (Williamson). (After Miss Berridge.)] Of the two species included by Scott in his genus _Spencerites_ only one, _S. insignis_, need be considered. Since the publication of Scott’s paper our knowledge of this type has been extended by Miss Berridge[442] and by Prof. Lang[443].