374 BOTANICAL GAZETTE [october 



Coal Measure plants. — Our knowledge of the flora of the British Coal 



Measures 



Kidston^ 



Arber. 5 The former paper is devoted to a description of the plants secured 

 from the beds cited in the title. Among the forms referred to the ferns, 20 

 genera are included, represented by about 60 species. New species are de- 

 scribed under Sphenopteris, Pecopteris, and Neuropteris; while a new sporan- 

 gium genus (Coseleya) is proposed, which may represent the microsporangium 

 of one of the Cycadofilicales. Among the Equisetales, 7 genera are included, 

 represented by 25 species, among which is a new species of Palaeostachya. The 

 Lycopodiales are represented by 12 genera, including 34 species, among which 

 are new species of Sigillaria and Lepidocarpon. There is also a new Sphe- 

 nophyllum. The Cordaitales are represented by 9 species. Eight new seeds 

 are . described under Samaropsis, Tripterospermum (2), Polypterospermum, 

 Lagenostoma (2), Rhabdocarpus, and Hexagonocarpus. A new species of 

 Whittleseya, a genus usually referred to Ginkgoales, calls forth the opinion of 

 the author that it is more related to Cycadales. 



Arber's paper, as its title implies, is more concerned with the geology of 

 the beds investigated, but it lists a large number of the plants that are made 

 the basis of conclusions as to comparative stratigraphy. Among them two 

 new species of Sigillaria are described. — J. M. C. 



The embryo sac of Peperomia. — Fisher 6 has extended our knowledge of 

 the embryo sac situation in Peperomia by a study of additional species, chiefly 

 from Jamaica. The investigation included 8 species of Peperomia and also 

 Piper tuberculatum. In all the species of Peperomia the mature sac is 16- 

 nucleate, one nucleus maturing as the egg nucleus, another one as a synergid, 

 6-9 fusing to form the primary endosperm nucleus, and the remainder cut off 

 individually by walls and later degenerating. In connection with the first two 

 divisions of the mother cell, evanescent walls appear and reduction occurs, the 

 conclusion being clear that the first 4 nuclei of the sac are megaspore nuclei. 

 In Piper the mature sac is 8-nucleate, and is developed directly from the 

 mother cell. 



The author reaches the general conclusion that all of the peculiarities of 

 the sac are derived, and that therefore the embryo sac of Peperomia does not 

 represent a primitive condition. — J. M. C. 



* Kidstox, R., On the fossil flora of Staffordshire coal fields. III. The fossil 

 flora of the Westphalian series of the South Staffordshire coal fields. Trans. Roy. 

 Soc. Edinburgh 50:73-190. pis. 5-16. 1914. 



5 Arber, A. E. Newell, On the fossil floras of the Wyre Forest, with special 

 reference to the geology of the coal field and its relationships to the neighboring Coal 

 Measure areas. Phil. Trans. Roy. Soc. London B 204:363-445. pis. 26-2Q. 19**- 



'Fisher, G. Clyde, Seed development in the genus Peperomia. Bull. Torr. Bot. 

 Club 41:137-156, 221-241. pis. 3-6. 1Q14. 



