CRYSTALLOGRAPHY 56 1 



prepared from the hydrate (J. A. Hedvall, Zeil. anorg. Chem., 

 120, 87, 1922). 



H. C. Burgen, by the use of the same methods, has shown 

 that both tungstic WO, and the hydrate HjWO, are crystalline 

 and have different structures, while similar results are obtained 

 for the hydrates H4W0jand HaMoO^ {ibid., 121, 240, 1922). By 

 means of Debye and Scherrer's method, J. W. Mellor and W. 

 H. Bragg [Eng., 114, 456, 1922) have confirmed the view 

 previously advanced by the former, that kaolinite breaks up, 

 on heating to 500 "^ C, into an amorphous mixture, the crys- 

 talline structures being well defined in material heated to 

 temperatures below 500° C, but non-existent in those heated 

 above that temperature. 



BOTANY. By E. J. Salisbury, D.Sc, F.L.S., University College, London. 



Taxonomy. — A new species of Statice (S. anfrada) from the 

 Dalmatian coast is described by Salmon in the Journal of 

 Botany for December. It is most closely allied to S. remotis- 

 spicnla of Lacaita from which it differs in the numerous sterile 

 branches, more zig-zag scape and the form of the bracts. 



In the same journal Miss Lyle describes a new genus of 

 marine algae, closely allied to Antithamnion , termed Anti- 

 thamnionella. In the possession of two kinds of branches, 

 alternate and verticillate, the latter genus agrees with the former, 

 but approaches Callithamnion and Spermothamnion in the 

 triangular division of the tetraspores. Three species are 

 recognised of which A. sarnensis is new, whilst A. ternifolium 

 and A. veriicillatiini were doubtfully referred by De Toni to 

 Antithamnion. The distribution of the three species is inter- 

 esting. All three are epiphytes and have been found respec- 

 tively in Guernsey, the Cape of Good Hope, and Cape Horn. 



The Report of the Botanical Society and Exchange Club, 

 vol. vi, Part III, contains a paper on the British Centaureas of 

 the Nigra group by C. E. Britton. the following are recog- 

 nised : C. obscura Jord., in which he distinguishes four forms 

 of the type, var. subnemoralis with one form ; Centanrea 

 surrejana sp. nov. ; C. Drucei sp. nov. with five forms ; C. 

 nemoralis with var. diversifolia and four forms, and V. sub- 

 integra and three forms, V. minima with a radiate form, V. 

 rnicroptilon, V. Debeauxii. In the same journal Dymes 

 describes the seeds of the British Dactylorchids, and in a 

 supplement Druce gives a list of Shetland plants numbering 

 505. This number is exclusive of 70 species previously 

 recorded, but probably mostly errors of identification. Of the 

 total, 446 are regarded as native. 



Ecology and Distribution. — Osmaston, in the Journal of 

 Ecology for November, describes the vegetation of the Garhwal 



