142 RECORDS OF THE AUSTRALIAN MUSEUM. 



veins in the leaves, although it is conceivable that the ' cross- 

 wrinklings ' may be veins. I do not think that the two are 

 identical, but the plant is worth referring to. Schmalhausen 

 regards his plant as a Conifer comparable to Sciadopiiys {'JJm- 

 brella Pine ')." These are the only comparisons I am able to 

 suggest. 



When first dealing with this fossil, I came to the conclusion 

 that it was a Fern of anomalous structure, probably a new 

 genus, but my difficulties were increased on the preparation of 

 the micro-sections of the stem, for I at once saw that the struc- 

 ture revealed was not that of an ordinary Fern. I accordingly 

 forwarded notes and copies of the illustrations to ^Nlr. Seward, 

 who in an exceedingly kind manner has solved my doubts in the 

 letter already referred to, as follows: — ^"The internal structure 

 strikes me as particularly interesting; your figures 10 and 11 

 suggest a fairly broad zone of secondary wood — a form of structure 

 practically unknown among recent Ferns, V)ut slightly developed 

 in some species of Botrychium, which have undoubted secondary 

 thickening. From Permian and Coal Measure rocks we have, 

 however, several genera of plants which possess characters now 

 shared by Cycads and Ferns, e.g., Lygiiiodendron, Heteraiigium, 

 Poroxylon, and others ; in the first two the leaves are of the type 

 long known as Sphenopteris elegmis Siud other forms, and the stems 

 have a broad zone of secondary wood, M'ith a structure like that 

 of living Cycads. These intermediate types have recently been 

 placed by Potonie in a special class, which he calls Cycadofilices ; 

 the genera have been described by Williamson and Scott, Renault, 

 and others. It would seem not improbable that your plant may 

 belong to this class ; it certainly suggests a Fern with secondary 

 wood. It would be very interesting to know more about the 

 anatomy, whether the wood consists of radial rows and tracheids 

 separated by broad bands of medullary ray tissue — as in Cycads, 

 or, if it is of the moi'e compact form, with narrower and less obvious 

 rays, such as we have in Conifers ; also what the tracheids look 

 like in longitudinal section." 



Mr. Seward's remarks suggest comparison with Botrychhim. 

 The structure of the stem in this genus is thus described* by Dr. 

 D. H. Campbell : — " The vascular bundles of the stem are much 

 more prominent than in Ophioglossum, and form a hollow cylinder 

 with small gaps only corresponding to the leaves. This cylinder 

 shows the tissues arranged in a manner that more nearly resembles 

 the structure of the stem in Gymnospermes or normal Dicotyledons 

 than anything else. Surrounding the central pith is a ring of 

 woody tissue, with radiating medullary rays, and outside of this a 

 ring of phlcem, separated from the xylem by a zone of cambium, 



* Mosses and Ferns, 1895, p. 243. 



