60 SCIENCE PROGRESS. 



Before leaving the Permian period, a brief reference 

 should be made to the recent examination of the Autun 

 "Boghead" by Renault and Bertrand 1 ; these authors 

 published a detailed account of this carbonaceous deposit 

 in 1892, 2 and more recently a further note on the same 

 subject. They point to the existence of a characteristic 

 gelatinous alga in the Autun beds, and consider that the 

 species lived in enormous numbers in the Permian lake 

 of Autun, and was mainly responsible for the accumulative 

 of the boghead. To this alga they have given the name 

 Pila bibractensis. In the Kerosene Shales of Australia 

 another alga, Reinschia Australis, appears to have played a 

 corresponding part, and in the Scotch " Torbanite " another 

 species of the genus Pila. 



In Saporta's classic work on the Jurassic flora of France 3 

 there are some figures of an interesting type of plant de- 

 scribed as Williamsonia Morieri Sap. A well-preserved 

 specimen has recently been examined by M. Lignier, with 

 the result that the name Bennettites is substituted for 

 Williamsonia. The structure closely corresponds with that 

 of B. Gibsonianus Carr, recently described afresh by Count 

 Solms. 4 Lignier makes some important statements as to 

 the morphological value of the seed-bearing peduncles, and 

 concludes that the specimen is a gymnospermous inflores- 

 cence, which lends support to the distinctions insisted on by 

 Solms between Bennettitce and Cycadea. A further com- 

 munication is promised by M. Lignier on this subject. 



Mr. T. H. McBride, in a recent number of the American 

 Geologist? has published a photograph and brief description 

 of a new form of Bennettites, B. Dactejisis, from South 

 Dakota, probably of Lower Cretaceous age. 



■ l Cotnpi. Rend., vol. cxvii., 1893, p. 593. 



1 Soc. Hist. Nat. d' Autun, vol. v., 1892, p. 159. 



8 Pal. Franc. See also Saporta and Marion, devolution du regnc 

 vegttal, vol. i., 1885, p. 244. 



4 Annals Pot., vol. v., 1890-91, p. 419. 



' Compt. Rend., vol. cxvii., 1893, P- 867. 



(i Vol. xii., 1893, P- 2 48. 



