On ike Fossil Plants of ths Coal-measures. G3 



enlarged, so as to make the entire section an almost hexagonal one. 

 This axis is surrounded, as in AsterophijlUtes, by a double bark — an 

 outer prosenchymatous one, and an inner one of more delicate 

 cellular structure. At each node tliis bark expands into a lenti- 

 cular disk fringed with stiff narrow bracts, which extend upwards 

 and outwards beyond the sporangia. The latter rest upon the 

 bractiferous disks and the basal portions of the bracts, each verticil 

 being fertile. The sporangia are closely packed in about three 

 concentric circles, and attached by sporangiophores originating from 

 each side of the base of each bract. The sporangia have cellular 

 walls; they are full of large spoi'es, each of which has its sur- 

 face prolonged into a number of very long radiating spines. This 

 fruit the author unhesitatingly identifies with, the aerial stems 

 previously described. 



He then examines various so-called VolhmannicB found in the 

 Lancashire Carboniferous shales, of which the internal structure 

 is not preserved, but which, being found ^vith leaves attached 

 to them, admit of no doubt as to their belonging to AsterophyU 

 lites. These are regarded as being identical -^-ith Volhnannia 

 Dawsoni ; hence the author accepts the latter fruit as giving the 

 internal organization of the ordinary Asterophvlhtean strobilus. The 

 fruit (which has been previously described by Binney, Carruthers, and 

 ISchimper, under the names of C'alamodendron commune, Volkmannia 

 Blnneyi, and Calamostachys Binneyana) is then investigated. The 

 above authors had associated it vvith Calamites ; but its internal 

 structure is shown to have nothing in common with that type. 

 It consists of alternating verticils of barren and fertile appendages. 

 The former are nodal disks beamig protective leaves ; the others 

 are verticils of sporangiophores, usually six in each verticil, and 

 which closely resemble those of the recent Equisetacese ; they 

 project at right angles from the central axis, and expand at their 

 outer extremities into shield-like disks, which sustain a circle of 

 sporangia on the inner surface of each shield. The sporangia 

 consist of a very peculiar modification of spiral cells ; they are 

 filled with spores which have been described as provided with 

 elaters, like those of Equisetum ; but the author rejects this in- 

 terpretation, regarding the so-called elaters as merely the torn 

 fragments of the ruptured mother cells in which the true spores 

 have been developed. The vascular axis is sbown to be solid, and 

 without any cellular elements, being wholly different from that of 

 Calamites, in which the \ascular axis is a hollow cylinder con- 

 taining an immensely large cellular and fistular pith. In one fine 

 example of Calamostachys Binneyana the author has found the cen- 

 tral fibro-vascular bundle surrounded by an exogenous ring. This, 

 too, exhibits no resemblance whatever to the correspondiTig growths 

 of Calamites ; on the other hand, it corresponds closely with 

 conditions occurring in some parts of Asteropliyllites, to which 

 group the author believes the fruit to be related, notwithstaiiding 

 the peculiarity of its sporangia and sporangiophores. The au- 

 thor is confinru'd in his conclusion tlmt (his fruit is not Cala- 



