176 
Fig. 34 (228, Coal Creek Mine, Korumburra).—This represents one of 
several flattened fragments, slightly more than 3mm. in breadth, found in close 
association with the Rhizomopteris , and which may be portions of petioles 
originally attached to the large oval scars shovm in Figs. 30-32. 
The specimens may be regarded as fragments of a fern stem or rhizome, 
which bore scattered fronds, each of which was traversed by a single stele of a 
broadly U-shaped form similar to that of a frond of Todea or Osmunda. The 
small circular scars (Fig. 30a) probably mark the points of origin of numerous 
adventitious roots which clothed the stem as in recent species of Osmundaceae, 
and the still finer dots, shown in Fig. 32, may possibly indicate the presence of 
hairs or ramenta. It is impossible to connect this stem with any particular type 
of frond, but there is the possibility that Rkizomopteris Etlieridgei is a young 
stem which bore leaves of the type Cladopklebis denticulata, var. australis, a 
fern which is not improbably a member of the Osmundaceae. But, in the absence 
of evidence as to the fronds borne by R. Etheridgei, we must for the present 
regard the fragments shown in Figs. 30-34 as probably those of a fern of 
doubtful systematic position. 
Locality .—Coal Creek Mine, Korumburra. 
Fragments of Fern Fronds. 
1. Specimen 219, from allotment 30, parish of Jumbunna East, repre¬ 
sents a small fern frond in the form of a circinately coiled rachis. 
2. Specimen 210, from peg 267, parish of Jumbunna East, is no doubt 
part of a fern rachis with portions of a few pinna axes, but with no trace of 
pinnules ; the collection includes several other fragments, e.g., 132, Elms 
Creek, Jumbunna East; 155, allotment 53a, Jumbunna; 186, allotment 32a, 
Kongwak; 200, allotment 1, Kongwak, which may probably be those of the 
rachises of ferns. 
3. Specimen 127, east of Foster River, Moyarra.—A portion of a pinna of 
a frond too small to determine. 
CLASS GINKGOALES. 
This division of the Gymnosperms is now generally adopted as the best 
means of expressing the isolation of the solitary existing species Ginkgo biloba, 
the Maidenhair Tree. It is customary to make use of the generic name Ginkgo 
for the numerous fossil leaves which in form and venation are often indistin¬ 
guishable from the recent species. Braun’s genus Baiera is applied to leaves 
resembling Ginkgo in shape, but differing in their narrower and more numerous 
segments ; while it is convenient to retain this name for certain forms of leaves 
it must be recognised that the distinction between Ginkgo and Baiera is one 
of degree, and the choice of one or other term is decided by characters of little 
or no importance. 
The occurrence of transitional forms between more or less entire leaves, 
such as occur abundantly in the Maidenhair Tree (Ginkgo biloba) and like 
Ginkgo antarctica, Sap.,* among fossil types, and those with a much divided 
lamina with narrow segments, demonstrate the impossibility of strictly defining 
the limits of the two genera. 
* 
Ratte (88 3 ), PI. III.; Shirley (98), PI. I. 
