Palaeontologie. 165 



there are some curious, puzzling forms. The further careful study 

 of these fossils will certainly prove te be of highly scientific interest, 

 It seems too, that the discovery of these beds has an important 

 bearing on the broad geologic problem of the origin and develop- 

 ment of petroleum and related carbonaceous Compounds. 



Jongmans. 



Sahni, B., On the Branching ofthe Zygopteridean Leaf, 

 and its Relation to the probable 'Pinna' Nature of 

 Gyropteris shiuosa, Goeppert. (Ann. Bot. XXXII. p. 369—379. 3 

 text figs. 1918.) 



The author brings forward a new view of the branching ofthe 

 Zygopteridean leaf, which is opposed to the interpretation given 

 by Paul ßertrand and by Kids ton and Gvvynne-Vaughan. 

 He considers that there are in all Zygopterideae, as in all known 

 plants with pinnate leaves, only two rows of pinnae (secondary 

 raches), one on each side of the leaf. The supposed secondary 

 raches of Stauropteris, Metaclepsydropsis, Diplolabis, Dineuron and 

 Elapteris are really tertiary (pinnules), and the result of the forking 

 of the true secondary raches. The latter are completely fused to 

 the primary rachis, but their Strands ('pieces sortantes' of 

 Bertrand) are distinct. This conclusion revives the Suggestion 

 that Gyropteris sinuosa, Goeppert, is a secondary rachis of a form 

 like Metaclepsydropsis or Diplolabis, in which this organ acquired a 

 cortical sheath independent of the primary rachis. 



The mode of the branching of the Stauropteris leaf is found to 

 conform (as in the other Zygopterideae) to the rectangular system 

 ('edification rectangulaire', P. Bertrand). The laminated 

 portions of the Zygopterid leaf were probably held in a more or 

 less horizontal position, with all the segments expanded in the 

 same plane, as in the modern Ferns. 



Unger's genus Clepsydropsis (1856) is extended to include the 

 genus Ankyropteris , P. Bertrand (1909) and is divided into two 

 sectors named after the two original genera. 



The Zygopterideae are divided, on the basis of the vascular 

 structure, into the two sub-families Clepsydrodeae and Dineuroideae , 

 after the names of their most primitive genera. The relations of 

 the genera are shown in a table based on a modification of P. 

 Bertrand's latest scheme. Agnes Arber (Cambridge). 



Scott, D. H., Notes on Calatnopitys, Unger. (Journ. Linn. Soc. 

 Bot. XLIV. p. 205-232. 3 pl. 1 text fig. 1918.) 



The object of the present Notes is firstly to put on record some 

 fresh evidence as • to the course of the leaf-trace in C. aniericana, 

 and secondly to discuss the relations of the various species, with 

 special reference to Dr. Zalessky 's proposed division ofthe genus 

 (Zalessky, M. D.: Etüde sur l'Anatomie du Dadoxylon Tchihat- 

 cheffi. Mem. du Comite Geol., Nouvelle Serie. Livr. 68. Petrograd, 

 1911.) 



It is shown that in Calarnopitys ainericatia the leaf-trace, after 

 separating from the reparatory Strand, divides into two in tra ver- 

 sing the Zone of secondary wood. It thus differs from the trace of 

 C. Saturni, in which division is only completed beyond the zone 

 of thickening. 



