GINKGOALES 



^85 



Usually only the leaves are found, and they are very seldom 

 attached. They differ from the living Ginkgo in being more deeply 

 incised and in having narrower lobes. The venation is as distinctly 



Fig. 197. — Baiera gracilis: the leaf is bilobed, but each of the two lobes is repeatedly 

 dichotomous; natural size. — After Renault.''^5 



dichotomous as in the ferns 



(fig- 197)- 



The seeds are borne on a 

 branching axis, usually with 

 several seeds on an axis. 

 Some of the figures, which 

 seem to give the shape very 

 accurately, do not show any 

 collar (fig. 198^). 



The microsporangia were 

 in strobili consisting of sev- 

 eral sporophylls, each with 

 several microsporangia. In 

 younger stages, the sporo- 

 phylls, with their microsporangia, closely resemble those of the liv- 

 ing Ginkgo, except that there are generally six or more sporangia 

 on a sporophyll (fig. 1985 and C). 



Fig. 198. — Baiera miinsteriana: A, five un- 

 ripe seeds; B, portion of male strobilus with 

 three sporophylls bearing several microspo- 

 rangia, shortly before shedding pollen; C, 

 similar specimen at a later stage. Rhaetic 

 from Bayreuth. — After Schimper-Schenk.5<« 



