390 Walton.—On a New Method of investigating Fossil 
IV. Sphenopteris nummularia. A portion of a frond is described in 
which nothing but the transparent cuticle and traces of the lignified 
tracheides in the vascular strands are preserved. Stomata of the usual type 
are described. 
V. Oliocarpia gntbieri. Preparations showing sterile and fertile pinnae 
are figured, also sporangia exhibiting an apparently uniseriate annulus. 
Stomata of the usual type are recorded. 
VI. A fungus (spore-form) is figured. It is suggested that, by a careful 
study of the position of the hyphae of such fungi, it may be possible to 
deduce something about the vicissitudes through which the plant fragment 
has passed before fossilization. 
In conclusion, I have to thank Prof. Seward for a great deal of helpful 
criticism given in the course of this work, and Mr. H. Hamshaw Thomas 
for invaluable advice in matters of technique and for many of the specimens, 
some of which he kindly identified. 
I am indebted to several members of the staff of the Sedgewick 
Museum, Cambridge, for the loan of specimens and for references to 
literature. 
Bibliography. 
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Geol. Mag., Decade V, vol. iv, No. 520, October. 
Gothan, W. (1915): Uber die Methoden und neuen Erfolge bei der Untersuchung kohlig erhaitener 
Pflanzenreste. Sitzungsb. d. Ges. Naturforsch. Freunde, Berlin, Jahrg. 1915, No. 2. 
Halle, T. G. (1911) : On the Fructifications of Jurassic Fern-Leaves of the Cladophlebis denticulata 
Type. Arkiv for Botanik, Band x, No. 15. 
Huth, W. (1913) : Zur Kenntnis der Epidermis von Mariopteris muricata. Zeitschrift d. Deut. 
Geol. Gesellschaft, Band lxv, No. 3. 
Kendal, P. F. (1922) : The Physiography of the Coal Swamps. President's Address, Section C, 
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Roy. Soc., Edin., vol. li, pt. iii, No. 24, 1917. 
Nathorst, A. G. (1902) : Tertiare Pflanzenreste aus Ellesmereland. Report of the Second 
Norwegian Arctic Expedition in the Fram , 1898-1902, No. 35. 
(1907) : Kollodiumaftryck sasom hjalpmedel vid undersokning af fossila vaxter. 
Geol. Foren. Forhandl., Bd. xxix. 
Oliver, F. W., and Scott, D. H. (1904) : On the Structure of the Palaeozoic Seed Lagenostoma 
Lomaxi. Phil. Trans. Roy. Soc., London, Ser. B, vol. cxcvii. 
Schulze, F. (1855) : Uber das Vorkommen wohl erhaitener Zellulose in Braunkohle und Stein- 
kohle. Bericht fiber die zur Bekanntmachung geeigneten Verhandlungen der Konigl. 
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