1869.] CARKUTHEES' — SIGILLAEIA. 263 



In conclusion, we may inquire what light the reproductive organs 

 figured by Goldenberg throw upon this question. These consist of 

 several small sporangia borne on the dilated bases of slightly altered 

 leaves. The sporangia in size and form agree exactly with what I 

 have described in Flemingites ; but their arrangement on the sup- 

 porting leaves is very different in the two genera. In Flemingites 

 they are borne in a double row on the horizontal portion of the 

 leaves which form the cone. I have recently detected similar spo- 

 rangia associated with a true Lepidodendroid plant from a Carbo- 

 niferous deposit from the South of Brazil. That these sporangia 

 belonged also to the genus SigiUaria is very probable, independent 

 of the direct observations of Goldenberg, from the enormous quan- 

 tity of these capsules which occur in some coals, imparting to 

 them special valuable properties. 



Dr. Dawson says he has never found the detached fruits (^Trigo- 

 nocarpum and JRhahdocarjpus) which he associates with Sigillaria 

 attached to them ; and we need not, therefore^ consider what claims 

 they have to be so considered. 



The structure of the fi'uits of Sigillaria and allied genera may be 

 characterized as follows : — 



Triplosporites, H. Br. Cone with a single sporangium borne on 

 each scale ; the sporangia of the upper portion of the cone containing 

 microspores, while those of the lower portion contain macrospores. 



Lejpidostrohus, Brongn. Cone with a single sporangium on each 

 scale ; all the sporangia filled with microspores. 



Flemingites, Carr. Cone with a double series of small sporangia on 

 each scale. 



Sigillatia, Brongn. Cone with a single patch of small sporangia 

 on the enlarged base of the scale. 



It is probable, from the recent observations of Brongniart, that we 

 as yet know the macrospores of only one genus, viz. Triplosporites, 

 K. Br. ; but this would correspond with the state of our knowledge 

 regarding the similar organs in the living Lycopodiacece ; for of the 

 two principal genera of this Order, the microspores only are known 

 in Lycopodium, while both kinds of spores occur in Selaginella. 



EXPLANATION OF PLATE X. 



Eigs. 1-3. Erom a specimen of Stigmaria in which the whole of the cellular 

 tissue had decayed and the spaces occupied by it had been filled 

 with amorphous clay ; thereafter tLe vascvdar cylinder itself de- 

 cayed, exposing the form of the meduUaiy axis and the meshes for 

 the vascular bundles. Eig. 1. Longitudinal section, showing that 

 the meshes proceeded outwards at right angles to the axis. Eig. 2. 

 The easts of the meshes, seen from above. Eig. 3. Ditto, seen 

 from below. 



Figs. 4-7. From a specimen of Stigmaria in which the vascular tissue is well 

 preserved, but all the cellular structure has been replaced by amor- 

 phous material. Eig. 4. Transverse section of the vascular cyUnder. 

 Eig. 5. Oblique perpendicular section, gradually sloping outwards 

 from above dowTiwards. The vascular bundle is seen as a ridge at 

 the base of the triangular cavity. This vascidar ridge produces 

 the double structure in the cast of the cellular cavity as seen from 



t2 



