July 11, 1919] 



SCIENCE 



45 



The Devonian species belong to the oldest 

 land-flora so far described from English strata. 

 A paper by Messrs. Don and Hickling^ gives 

 by far the best account we possess of Parha 

 decipiens, a problematical Old Eed Sandstone 

 discovered in 1838 and referred to different 

 positions in both the animal and vegetable 

 kingdoms. It occurs, in the form of flat cir- 

 cular or oval flattened mummified bodies en- 

 closing numerous circular groups of spores, 

 in the lower beds of the Caledonian Old Eed 

 Sandstone and in passage beds between the 

 Old Eed and Siliu-ian. The authors make 

 out a good case for its inclusion in the Thallo- 

 phyta as an extinct type with Algal affinities. 

 Mr. Don, a student of unusual promise, ob- 

 tained a conunission in the early days of the 

 war and died at Salonika in April, 1916. 



2. Carboniferous Plants. — Additions have 

 been made to our knowledge of Carboniferous 

 floras by several authors. Dr. Kidston" pub- 

 lished in 1916 the first of a projected series 

 of papers on plants from the Scottish Coal 

 Measures in which are described two new spe- 

 cies of Sigillaria, two new types of Sphenop- 

 teris, and a new species of seed referred to 

 the genus Lagenospemum. The same author^ 

 has described several plants from the Forest 

 of Wyre coalfield and from the Tetterstone 

 Clee Hill coalfield. Dr. Arber^ in a paper 

 dealing with plants from the Eed Clay series 

 and the Middle Coal Measures of the Stafford- 

 shire coalfield proposed a new generic name, 

 Calamophloios, for casts and impressions of 

 Calamite stems in which the external surface 

 and not the surface of the pith-cast is pre- 

 served. These papers on Carboniferous floras 

 supply important data towards a more com- 

 plete classification of coal-bearing strata in 

 Britain on the basis of the fossil plants. Miss 

 Lindsay^ contributes new facts in a short 



Jour. Geol. Soc, Vol. LXXI., Pt. IV., p. 

 648, 1917. 



6 Trans. S. Soc. Ediiiburgh, Vol. LI., Pt. III., p. 

 709, 1916. 



7 lUd., Pt. IV., p. 999, 1917. 



8 Phil. Trans. B. Soc. London, Vol. 208, Series B, 

 p. 127, 1916. 



» Annals of Botany, Vol. XXIX., p. 223, 1915. 



accomit of the method of branching and the 

 phenomena of branch-shedding in Bothroden- 

 dron. 



Dr. Scott in an interesting sketch of the 

 forests of the coal age^" discusses the evidence 

 afforded by paleobotanieal investigations on 

 the conditions under which the plants grew; 

 he draws attention to the high degree of or- 

 ganization exhibited by Paleozoic species, a 

 fact which has not hitherto been sufficiently 

 realized in discussions of problems connected 

 with evolution. The same author^^ has pub- 

 lished a valuable and comprehensive account 

 of the genus Seterangium, one of the best 

 loiown examples of the very important extinct 

 Paleozoic group of pteridosperms, plants with 

 fern-like foliage-bearing seeds and possessing 

 anatomical characters' denoting a close affinity 

 to gymnosperms. He institutes a new sub- 

 genus Polyangium to include several species 

 characterized by compound leaf-traces and 

 other distinctive features in contrast to an- 

 other set of species, in which the leaf-trace is 

 single in origin, refeiTed to the subgenus Eu- 

 Heterangium. The Polyangium forms indi- 

 cate a closer relationship between the Lygin- 

 opteridese and the Medulloses and Calamo- 

 pityese than has hitherto been suspected. This 

 paper is an admirable example of the im- 

 portance of revising from time to time in 

 the light of fresh discoveries our knowledge 

 of extinct genera. Dr. Scott^^ has recently 

 described a new species of another Carboni- 

 ferous genus founded on petrified stems, Meso- 

 xylon multirame, characterized by the 'presence 

 of many axillary shoots and other morpho- 

 logical features. A preliminary account is 

 added of a small stem associated with Mitro- 

 spermum seeds which it is believed may be- 

 long to Mesoxylon. Dr. Nellie Bancroft's care- 

 ful re-investigation of Williamson's Eachi- 

 opteris cylindrical^ from the Lower Coal 

 Measures of Yorkshire reveals the existence 

 of two tjrpes of this fern which she regards 



10 Trans. Instit. Mining Engineers, Vol. LIV., 

 Pt. II., p. 33, 1917. 



11 Jour. Linn. Soc, Vol. XLIV., p. 59, 1917. 



12 Annals of Botany, Vol. XXXII., p. 437, 1918. 



13 md., Vol. XXIX., p. 531, 1915. 



