KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 51|. N:0 7. 11 
No complete specimens of Antholithus Zeilleri were found which could throw 
any light upon its construction, but, on the other hand, I found some of a somewhat 
different aspect from those described by Professor NATHORST. 
As Professor NATHORST thought he had to do with the male flower of a Gink- 
gophyte, he called the structures in question ”Staubblätter. Later on I will point 
out some facts speaking for Antholithus Zeilleri being the male organ corresponding 
to Lepidopteris Ottonis. Presuming this affinity, it would either be lobes of a fertile 
frond, such as in the Pteridosperms, or itself constitute differentiated sporophylls. 
Microsporophylls or lobes of fertile frond reaching a length of 15 mm., attached 
several together; position in other respects unknown. Each lobe or sporophyll con- 
sisting of a 5 to 7 mm. long, narrow, stalk-like portion, divided into from 3 to 5, 
generally 4, segments. HNSegments up to the length of 6 mm., linear with rounded 
apex, or very short and broad, ovate. Each segment bearing in the middle line of the 
lower side ovate pollen-sacks; these directed obliquely outwards, opening with a longi- 
tudinal fissure. Pollen-grains ovate. Cuticle of sporophylls or lobes rather thick, 
composed of isodiametrically polygonal or somewhat oblong cells, sometimes having, 
sometimes lacking papillae. Stomata bordered by a ring of 4 to 6 regular subsidiary 
cells, sending out rounded cuticular lobes towards the centre of the entrance. Guard- 
-cells submerged below the epidermis. Cuticle of pollen-sacks with rather thin-walled 
oblong cells. 
The figures (pl. 3, figs. 1—9) should give a good idea of the size and the 
appearance of the structures in question. The stalk-like portion below the segments 
has the length of 5 to 7 mm.; it is narrow, somewhat increasing in breadth in the 
upper part. The number of the segments varies from three to five, though they are 
generally four. They sometimes reach a length of 6 mm., but more often they are 
shorter and at the same time broader; some, as can be seen, are ovate. 'The margin 
of the segment is not quite straight but has a couple of incisions on each side, 
which are hardly discernible with the naked eye (pl. 3, fig. 10). 
In spite of the variation in the number and the shape of the segments, there 
can be no doubt that all the specimens belong to one and the same species. 
No specimen gives any light as to how the lobes or sporophylls were placed; 
but it is evident from pl. 3, figs. 2 and 8 that they occurred several together, though 
their position cannot be more exactly stated. 
The pollen-sacks (pl. 3, figs. 1, 9) are ovate, and occur to the number of eight 
on each segment. They are attached to one side, probable the lower one, and are 
directed obliquely outwards. According to the length of the segments their position 
is somewhat different. In a short segment (pl. 3, fig. 1) they issue from a common 
point near the apex, and radiate, while in a longer one (pl. 3, fig. 9) they are in 
two parallel rows in the middle line of the segment. The opening took place by a 
longitudinal fissure, which extended all along one side and a short way down on the 
opposite one (pl. 3, fig. 9). 
