Palaeontoloofie. 93 



■'is 



that the petiole of this stem is Z. di-upsiloii. Dr. Kidston then 

 describes and figures evidence substantiating his allocation, pointing 

 out that "all the characters of the petiole trace found in the cortex 

 of Z. Gravi are identical with those of Z. diupsilon.^' 



M. C. Stopes. 



Kidston R. and D. T. Gwynne-Vaughan. On the Fossil 

 Osmundaceae. Part 4. (Trans. Roy. Soc Edinburgh XLVII. .3. 

 p. 455—477. pls. 1— IV. 1911.) 



The paper iirst deals with some specimens which should have 

 been included in part 1 had they been available. The deiailed 

 structure of the stele, the departure of the leaf trace, the structure 

 of the leaf trace and petiole, and the root of Osmumiites Kolbei 

 Seward are described. This specimen was found in Cape Colony, 

 in the Uitenhagen (Wealden) series, and was described from its 

 external features by Seward. Though considerably flattened the 

 internal anatomy is well preserved. The structure of the stele and 

 leaftrace and the root of O. Schemnitsensis Peltko is described 

 from Miocene specimens found at Illia by Prof. Zeiller. Ageneral 

 consideration of all the preceeding parts of the two authors' series 

 of papers foUows, and they give a table of the geological distribution 

 and Chief anatomical features of the fossil Osmundaceae. In the 

 general Remarks on the ancestry of the Osmundaceae they point 

 out that the vascular complexity of the cretaceous species was 

 greater than it is now in the living forms, and that possibl}'^ even 

 more complex structures existed within the family. 



The authors' main proposition is that the typical Osmundaceous 

 Stele was derived by medullation from a protostele with a primi- 

 tively solid xylem. They enter into a comparison with the Zygopte- 

 rideäe "and conclude that the two series are descended from a 

 common ancestor. The difficulty made by the Zygopterid leaftrace 

 is considered at length, and the Solution offered is the view that 

 the fern leaf of the Zygopterids took a more or less rigidly erect 

 habit. and the structure accomodated itself to that. The structures 

 of the Osmundaceae and Zxgopterideae as a whole are shown to be 

 far from "primitive". ' , M. C. Stopes. 



Prankerd, T. L.. On the Structure of the Palaeozoic 

 Seed Lagenostoma ovoides Will. (Journ. Linn. Soc. XL. 

 Botany N^ 278. p. 461-488. pls. XXII— XXIV. 3 text figs. 1912.) 



These small seeds, about 4.5 X 3 mm., are known in compa- 

 ratively great numbers, and have been described to some extent 

 by several writers since Williamson's time. The present paper 

 is based on a careful study of the University College coUection of 

 over forty specimens. From these sections were cut, sometimes 

 two from' the same seed. A detailed description and clear diagram 

 are given illustrating its form and shape, which in general features 

 is like that well known from L. Lomaxi. Meticulously detailed 

 descriptions of all the tissues follow, and a short account of an 

 infesting fungus. A concluding section is devoted to the theoretical 

 suggestions which the detailed work stimulates. These are princi- 

 pally in connection with pollination and the formation of the pollen- 

 chamber and lagenostome. This latter, unique structure which is 



