231 
$ 4 Miadesmia membranacea, Bertrand. 
Literature: Benson (13). 
The megasporangiate strobilus is composed of an axis 
with several sporophylls. 
At its base the fertile sporophyil has a groove in which 
the megasporange and a large and prominent ligule ly. 
Both are entirely covered by an indusium, arising in the 
proximal part of the leaf. Only at the apex of the spo- 
range an aperture is left in the velum, which is surrounded 
by numerous hairs. 
Within this thin membranaceous wall a single megaspore 
is found; in some cases the walls of the sporange and 
the containing megaspore were not to be distinguished, 
a feature comparable with a seed structure. 
The microporanges were not provided with a velum 
or integument as it is called by Benson (13). 
Pteridospermae. 
$ 5. Lagenostoma Lomaxi Will. 
Literature: Benson (14), Oliver and Scott (106, 107). 
Figure: 107. pl. 4—10. 
155p:257. 
Lagenostoma Lomaxi is the seed of Lyginodendron Old- 
hamium, the greatest specimens reach a length of about 
5,5 mM. with a diameter of 4,5 mM. They are attached 
to a pedicel and surrounded by an envelopment or cupule, 
which originates from the pedicel just below the base of 
the seed. In its lowest part the cupule envelopes the seed 
completely as a closed ribbed cup, but about half way up 
its height, it separates into a number of lobes or segments. 
