ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 329 



Thamnium Lemani, a Deep-water Moss.* — F. A. Forel has re- 

 ceived new specimens of Thamnium Lemani Sclinetzler, a moss which, 

 strangely enough, grows submerged at a depth of 200 feet in the Lake 

 of Geneva, on the south side of the lake, off Yvoire (Haute-Savoie). 

 They were dredged up in November 1906, in good vegetative condition, 

 and rooted to stones. This moss is the only known instance of a 

 green plant that vegetates at so great a depth in fresh-water, and is 

 a proof of the great depth to which daylight penetrates into water. 

 It is a derivative of the common species Thamnium alopecurum,. 



Some Critical Species of Pohlia.f — H. Busch treats of some species 

 of Pohlia which have recently undergone critical investigation : — P. 

 grandiflora Lindb. fil., P. proligera Lindb., P. annotina Liudb., 

 P. bulbifera Warnst. ; and he supphes a key for their determination. 

 He also calls attention to Mnium annotinum Leers, described in 1775, 

 and synonymous with Pohlia annotina Warnst., and Wehera Rothii 

 Correns. 



Classification of the Harpidia.| — F. Renauld continues the article 

 in which he describes the principles adopted by him in classifying 

 this difficult group of mosses. In a series of critical notes he treats 

 of the various species and forms, their relationships and distribution, 

 the modifying effect produced upon them by soil, climate, altitude, etc. 

 He urges that the forms should be studied in the field, rather 

 than in the herbarium. It is thirty years since he began to study 

 this group, at which time Schimper's " Synopsis " was the only book 

 that treated the group with any certainty ; it did not, however, go into 

 details. The further development has been elaborated mainly by 

 Eenauld and by Warnstorf in their respective systems of classification. 



Sphagnological Notes. § — J. Roll publishes a series of critical notes 

 on the results of recent researches upon the Sphagnacete, especially 

 the work done by Warnstorf and by Roth. He discusses innumerable 

 points of detail and differences of opinion. He asks, inter alia, what 

 the old Sphagnum acutifoliuyn Ehrh. ought to be called, now that 

 S. rubellum Wils., S. fuscum Klinggr., S. Schimperi Roll, S. robustum 

 Roll, S. plumulosum Roll, S. Warnstorfii Roll {S. patulum), S. Girgen- 

 sohnii Russ., S. Warnstor/li Russ., and S. subtile Warnst., have been 

 split off from it. He treats of the difficulties of the cuspidata group, 

 and of the still greater difficulties that beset the subsecunda group. 

 The members of this group he arranges in tabular form, with a brief 

 key. 



Index of Mosses. ||—E. G. Paris's Supplement to his " Index Bryo- 

 logicus," which was published in IDOu as a Memoire of the Boissier 

 Herbarium at Geneva, has been distributed, by the generosity of the 

 aforesaid Herbarium, as a free supplement to the first number of this 



* Arch. Sci. Phys. Nat. Geneva, xxiii. (1907) pp. 208-9. 



+ Medd. Soc. Faun. Plor. Fenn., 1905-6, heft 32, Helsingfors, 1906. 



% Rev. BryoL, xxxiv. (1907) pp. 7-14. 



§ Oesterr. Bot. Zeitschr., Ivii. (1907) pp. 96-106. 



11 Geneva : Georg. 1900, 334 pp. 



June 19th, 1907 z 



