Jurassic plants from Yorkshire, etc. 261 
F. Mossiana from the Potomac beds of Virginia, with veins which 
fork in the lower part of the leaf, then run parallel and near 
the apex converge and join up on a central line. This type may 
be perhaps related to the Yorkshire form but the peculiar course 
of the veins at the apex, which according to Fontaine is clearly 
‘seen, is quite a distinguishing feature. 
The only leaf bearing a close relationship to those before us, 
‘which I have found already figured, is the form recently described 
by Prof. Seward* from Afghanistan under the name of Podoza- 
mites Saighanensis. This leaf had a similar form and size to some 
of our examples, with a well-defined petiole and parallel veins 
1mm. apart, which branched near the petiole and converged 
slightly near the apex. 
In referring this form to Podozamites, Prof. Seward pointed 
out that it could be compared with the leaves of Ginkgoales 
especially with the Ginkgodium type. It is extremely probable 
that this leaf should be placed in the genus Hretmophyllum, though 
until more material is forthcoming it is impossible to determine 
whether it is specifically as well as generically identical with 
either of the Yorkshire species. 
It probably provides another example of a Jurassic genus 
with very discontinuous distribution. 
Among the numerous examples of Podozamites which have 
been figured, a few show some slight resemblance to our present 
form, but none show the gradual narrowing of the lamina into a 
distinct petiole. Some of the examples of P. lanceolatus possess 
similar nervation and a small petiolet. The sporophylls recently 
described by Nathorstt as Cycadocarpidium Swabi possess 
distant veins which fork near the base of the lamina and thus 
allow of a somewhat limited comparison. 
A comparison may also be made with the isolated leaves 
figured by Fontaine§ from Cape Lisburne, Alaska, under the name 
of Nageiopsis longifolia? Font., but which according to Berry|| are 
in nowise related to Nageiopsis. Fontaine's figure 5 might possibly 
be an Eretmophyllum leaf figured upside down, and the shape 
of the other fragments, their distant veins almost parallel but 
sometimes forking, present some points of similarity. 
It seems then that we are justified in regarding these York- 
shire leaves as types of a new genus of Ginkgoalian plants, which 
form a connecting link between Ginkgo or rather Ginkgodiwm 
and Feildenia or Phoenicopsis (if indeed these latter genera are 
members of the Ginkgoalian alliance). 
* Seward, (12), p. 35, Pl. rv. fig. 53. 
+ Heer (77), Pl. xxvut. figs. 3, 4, 5c. 
+ Nathorst (11), p. 5, Pl. 1. figs. 11—15. 
§ Fontaine in Ward (05), Pl. xiv. fig. 1—5. 
|| Berry, (10), p. 190. 
