512 Proceedings of the Royal Physical Society. 



of a racliis, to which probably the fruiting pinna was 

 attached. 



The sporangia are borne as a fringe at the margin of what 

 appears to have been an oval disk. This disk and, more 

 particularly, the sporangia appear to have possessed a con- 

 siderable thickness of tissue, which contrasts markedly with 

 the delicate structure of the barren pinnules. The sporangia 

 are converted into a bright, brittle, carbonaceous substance, 

 so that in splitting the stone in almost all cases they are 

 more or less fractured ; and, further, in no case where they 

 are at all well preserved have I been able to discover a 

 complete fruiting pinnule, one-half of each pinnule having 

 apparently adhered to each side of the matrix when the stone 

 was split. Thus there is only one-half of the disk with its 

 surrounding fringe of sporangia shown on the fossils and 

 their counterparts respectively. 



Figs. 4 and 5 represent each two fruiting pinnules, mag- 

 nified six and a half times. These figures are drawn under 

 the microscope with the camera lucid a, and every endeavour 

 has been taken to avoid any "restoration;" so that those 

 who cannot see the originals may form their own conclusions 

 from the drawings. 



Fig. 4 is an enlargement of the two fruiting pinnules 

 marked a in fig. 1. Both these pinnules, as already men- 

 tioned, are split through the middle, so that only half the 

 disk and its fringe of sporangia are shown. The sporangia 

 appear to have depended almost at right angles from the 

 margin of the supporting disk. In no case did I see any 

 trace of a thickened vein in the disk-like portion of the 

 pinnule like that figured and described by Zeiller (see fig. 9). 



Owing to the fruiting pinnules being split in two — and 

 this arises evidently from the comparatively thick mass of 

 coaly matter into which they have been converted — the 

 pinnules have the appearance of being attached to the 

 pedicels by their centre, within the fringe of sporangia; 

 but in reality I believe the pedicels are attached to the 

 outside edge of the fruiting pinnules, like a leaf to its stalk, 

 and that the pedicel is bent into a knee, which causes the 

 pinnule to assume a horizontal position. The apparent 



