332 SUMMARY OF CUERENT RESEARCHES RELATING TO 



of the whole paper. He also discusses Grunow's work on Stephanopyxis. 

 He considers that Pyxidkula (Dictyopyxis) heUenka and P. cruciata are 

 identical. 



Rhizosolenia.* — B. Schroder describes a new species of Rluzosolenia, 

 R. vktorise, from the Victoria Nyanza, It is the first record of the 

 genus from African fresh-water. It occurs singly almost always, 

 separating immediately after cell-dbvision. No microspores or auxo- 

 spores are known. It is nearly related to the Australian R. morsa, but 

 is larger, and has a calyptra witli a dorsal instead of a ventral curve, 

 and R. vktorise has the bristle longer and more bent. The median 

 bands are broader and less numerous than in R. morsa. 



Atlas of Diatomaceae.t — F. Hustedt publishes a continuation of 

 A. Schmidt's atlas of Diatomaceaj. In Heft 68 are four plates giving 

 enlarged figures of species of Tetracydus, TabeJlarki, Asterionella, 

 Ceratoneis, Rhaphkloneis, Eimotia, Navkula. In Heft 69 there are 

 four plates with figures of the following : — Tetracyclus, Euiiotki, Desmo- 

 gonium, CymnatopUura. 



Mediterranean Diatoms. | — J. Pavillard publishes some observations 

 on pelagic diatoms collected during the past five years by means of an 

 uninterrupted series of surface catches in the neighbourhood of Cette, 

 with a view to comparing the plankton of the Etang de Thau (pre- 

 viously studied by Pavillard) with that of the western Mediterranean. 

 He makes remarks on various species of Ghsetoceros, Rhizosolenia, Hemi- 

 aulus, etc., and describes some abnormahties. 



British Desmidiace8e.§ — W. and G-. S. West publish the fourth 

 volume of their monograph of the British Desmidiacese, giving descrip- 

 tions of the species, varieties, and forms of the following genera : — 

 Cosmarium, Xanthidium, Arthrodesmis, Staurastruni. The microscopic 

 structure of almost everything is figured, and frequently in colours. 



Desmidiacese.jl — AV. Migula publishes an elementary book on Desmi- 

 diaceae for the determination of the commoner species. He figures 246 

 species. The book belongs to a series of natural science handbooks. 



Dendroid Colonies of Desmids.l — F. Steinecke describes the occur- 

 rence of dendroid colonies of the following desmids in the Pechsee near 

 Berlin : — Micrasterias, Euastrum, Closterium. When shaken they became 

 broken up into individuals. The explanation was found to be the want 

 of oxygen in the water ; the algge were attempting to reach the surface. 



Pleodorina in France.** — E.Chattonhas discovered at Banyuls-sur- 

 mer Pleodorina calif or nica, hitherto recorded from California. It was 



* Ber. Deutsch. Bot. Gesell., xxix. (1912) pp. 739-43 (1 pL). 



t Schmidt, Atlas der Diatomaceen-Kuude. Leipzig : Reisland, 1911, Heft. 

 68, 69 (tab. 269-76). 



X BuU. Soc. Bot. France, Iviii. (1911) p. 21. 



§ Monograph of British Desmidiacese. London ; Ray Society (1912) iv. pp. 

 xiv. and 921 (pis. 96-128). 



II Die Desmidiazeen. Stuttgart : Franksche Buchlandung (1911) 65 pp. (7 pis.), 



•f Die Kleinwelt, ii. (1910) p. 16. 

 ** Bull. Soc. France et Belg., s6r. 7, xliv. (1911) pp. 309-331 (1 pi.). 



