220 
PROFESSOR W. C. WILLIAMSON ON THE ORGANIZATION 
more fortunate in discovering the fine specimen represented in fig. 25. Its mean 
diameter is nearly ’03. Its annulus (a) is obviously of the common type found amongst 
the Polypodiaceous ferns. b is clearly part of the peduncle ; hence the annulus has 
been a vertical one of the usual form, differing in this respect from the examples 
described by Mr. Carruthers. The interior of the sporangium is crowded with small 
spores, some of which are spherical, others apparently angular ; hut this latter appear- 
ance may merely result from defective mineralization. Fig. 26 represents one of the 
spherical spores enlarged 320 times. Their actual diameter is about •0018. This 
specimen is from the Oldham nodules. We have no clue to the frond to which it 
belonged. 
Figs. 27 to 32 exhibit the fructification of a Fern of an altogether different type. 
Figs. 27 & 28 represent lateral views of two sporangia of which a indicates the point 
of attachment. No peduncle is seen in any of the specimens, hence I presume that 
these sporangia have been sessile ones. They are slightly pyriform in shape, and their 
walls consist of large, strongly defined prosenchymatous cells. Fig. 29 is a transverse 
section of what appears to have been the upper part of the sporangium, and has passed 
through a horizontal annulus, whilst the internal cavity contains a small number of 
large spores. Fig. 30 is also a transverse section, but apparently made yet nearer to 
the upper extremity of the sporangium above the termination of the annulus. One 
solitary spore is seen within the internal cavity. The mean diameter of the two speci- 
mens, figs. 28 & 29, is '02. 
There can be no doubt that in these sporangia the annulus formed a conspicuous cap 
near the upper or free extremity of each sporangium. The spores are much larger than 
those of fig. 25, as is seen in figs. 31 & 32, which are drawn to the same scale as fig. 26. 
Each spore is about ’0023 in diameter, and consists of an outer cell wall (figs. 31 & 32, a) 
and an inner or primordial utricle (b). These sporangia are apparently of the type seen 
in the modern families of Gleichenieae and Schizeeeee, but especially approaching those 
of the latter family. Somewhat similar sporangia have already been figured by Cord a 
associated with his Senftenbergia elegans , and most probably also in the case of his 
Ilawlea 'pulcherrima. Speaking of the former plant, M. Brongniart says, “ Mais 
quoique ce genre fossile se rapproche beaucoup du Mokria. il en differe, non seulement 
par la forme generate de la fronde, mais surtout par les capsules, dont l’anneau elastique 
est forme, dans le MoTiria , d’un seul rang de cellules lineares, radiees, tandis que dans 
le Senftenbergia, d’apres M. Corda, il est compose de plusieurs rangees regulieres de 
cellules”*. The peculiar arrangement characteristic of Mohria and other allied genera, 
hut which is lacking in Senftenbergia, is precisely that which is seen in my examples f. 
* ‘ Tableau des genres des Yegetaux fossiles.’ 
t I am indebted to Professor Oliver, of the Ivew Gardens, for examples of Gleichenieae and Schizaseae, with 
which he supplied me for the purpose of comparison with my fossil specimens. This is only one amongst 
several instances in which my applications for assistance to the Kew establishment have received the most 
prompt and liberal responses. 
