Reports and Proceedings — The Royal Society. 383 



xxvi, p. 39, 1912). He also discusses the structure and affinities of 

 this Carboniferous fern, agreeing with Dr. P, Bertrand that it is 

 a member of the genus Anhyropteris. 



I. — The Koyal Society. 



Jime 27, 1912.— Sir Archibald Geikie, K.C.B., President, 

 in the Chair. 



'' A Petrified Williamsonia from Scotland." By Professor A C 

 Seward, F.E.S. 



The species Williamsonia scotica, which forms the subject of this 

 paper, is founded on a specimen from Upper Jurassic strata, probably 

 Kimeridgian, of Eathie, near Cromartjs in the county of Ross and 

 Cromarty, Scotland, where it was found by Hugh Miller, who 

 published a figure and brief description of it in the Testimony of the 

 Rocks. The type-specimen is in the Miller Collection, Royal Scottish 

 Museum, Edinburgh, and it is through the courtesy of the Director 

 that it has been possible to subject the fossil to anatomical investigation. 

 A small piece of the type-specimen is in the Geological Department 

 of the British Museum. 



The specimen has the form of an ovate strobilus, 1 1 cm. long, 

 with numerous linear bracts thickly clothed with long tubular hairs, 

 which form a dense felt between the bracts and between the bracts 

 and the axis of the cone. To the lower part of the peduncle are 

 attached spirally disposed bracts embedded in a packing of hairs. 

 The upper part of the strobilus axis, incomplete at the apex, is 

 invested by a layer, 2 mm, broad, of relatively long and narrow 

 appendages. Of these the great, majority are interseminal scales 

 polygonal in section, of almost uniform diameter, and ending distally 

 in a flat truncate apex. Regularly disposed among the scales are 

 slightly narrower and cylindrical megasporophylls, each mega- 

 sporophyll being the centre of a group of from five to six interseminal 

 scales. The megasporophylls consist of a central column of short 

 parenchymatous cells, corresponding to the seed-peduncles in 

 Bennettites, which becomes rather broader in the distal portion or 

 nucellus composed of longer and larger cells. The nucellus of 

 liomogeneous structure is closely invested by a single integument, 

 and this envelope overtops the conical apex as a broad micropylar 

 tube with a slightly funnel-shaped free end, in the centre of which 

 is a very narrow micropylar canal. 



A comparison is made with Williamsonia and Bennettites, especially 

 B. morierei (Sap. & Mar.), also with strobili described by Wieland 

 as species of Cycadeoidea. The question of the systematic position of 

 Williamsonia scotica is discussed, and the account concludes with 

 a consideration of resemblances between the Bennettitales on the one 

 hand and Gnetales and Ginkgoales on the other. Allusion is also 

 made to the possible relationship of this dominant Mesozoic group to 

 the Angiosperms. 



