Physiologie. — Palaeontologie. 277 



reiation which is found to hold between soil moisture residue and 

 atmospherjc evaporating power, are given and expressed in mathe- 

 matic formule. Harshberger. 



Scott, D. H., On Medullosa pusäla. {Proc. Roy. Soc. ser B'LXXXVII 



p. 221-228. pl. 13. 1914.; 



This species was provisionally named in Scott's 'Studies in 

 Fossil Botany', 1909, and a detailed account now appears. It differs 

 from MeduUosa nnglica principally in being much smaller, and in 

 some minor points, such as the simpler structure of the hypoderm 

 of the leaf-base. 



Lotsy's division of the genus MeduUosa into Pecoptero- and 

 NeuroptevomeduUosa is considered to be unsound, and a division 

 even on purely anatomical grounds is thought to be impossible 

 at present. W. N. Edwards. 



Seward, A. C, A contribution to our Knowledge of Weal- 

 den Floras, with especial reference to a Collection of 

 Plants from Sussex. (Quart. Journ. Geol. Soc. LXIX. p. 85 — 116. 

 pl. 11-14. 1913.) 



Several new species of plants recently obtained from the Fair- 

 light Clay, Sussex, are described, viz.: Lycopodites teilhardi, 

 Selaginellites dawsoni, Hausntannia pelletieri, Pelletievia valdensis 

 (gen et sp. n.), Teühardia valdensis (gen. et sp. n.) and Dichopteris 

 delicatula, while the plant formerly described by Seward as Conites 

 nnnatus is re-named C berryi. The new genus Pelletievia is repre- 

 sented only by fertile fronds, and is probably a member of the 

 Schisaeaceae , the sculpturing of the spores especially being of a 

 schizaeceous type. Teilhardia is a fern of doubtful afhnities. A füll 

 account of Selaginellites dawsoni appears elsewhere. In addition to 

 these the collection contains many good specimens belonging to 

 previously described species, such as Malonidium goepperti, Ruffor- 

 dia goeppevti (from both of which spores were obtained) and Ai'au- 

 carites pippingfordensis. The frond described in the "Wealden 

 Flora" as ? Zanites sp. is now identified with Pseudoctenis eathiensis, 

 Sew., and some fragments of Ctenis sp. are figured. These additions 

 bring the number of British Wealden plants up to about 70. 



A comparison of the floras of different regions shows that there 

 is great similarity between the Wealden of Europe and the cor- 

 responding N. American floras, but "the number of cosmopolitan 

 types is smaller than in the case of the Middle Jurassic floras." It 

 is also noteworthy that the Ginkgoales, though known from the 

 Wealden of Germany and elsewhere, have not yet been found in 

 England. W. N. Edwards. 



Stevenson, J. J., The Formation ofCoal beds. I. An Histo- 

 rical Summary of Opinion from 1700 to the present 

 time. (Proc. Am. Phil. Soc. L. p. 1 — 116. 1911). II. Some Ele- 

 mentarv Problems. (Ibidem. L. p. 519 — 643). III. The Rocks 

 of the Goal Measures. (Ibidem. LI. p. 423-553. 1912). IV. 

 (Ibidem. LH. p. 31-162. 1913.) 



A systematic account of the phenomena connected with the 

 formation of coal beds. The first part is a very excellent summary 

 of the literature of the last two hundred years. The second part 



