ZOOLOGY AND BOTANY, MICROSCOPY, ETC. i 89 



S. Demetrio nei Vestini (Prov. Aquila). It is rich in diatoms and 

 sponge-spicules ; and the diatoms are of the Cyclotella type and of the 

 Goscinodiscus type. 



Ceratium.* — E. Joergensen publishes a monograph of the genus 

 Ceratium, in which he maintains four sub-genera — Poroceratiiim, Bicera- 

 tium, Amphiceratiurn, Euceratium, and gives descriptions of the species 

 and varieties with their respective distributions. A detailed bibliography 

 is appended. 



Kammerplankton.f — R. Kolkwitz writes on the Kammerplankton 

 of fresh-water and of the sea. Taking the cubic centimetre as his unit 

 of measurement, he employs a plankton-chamber-slide of that capacity 

 for the quantitative estimation of the plankton in a given water," or at a 

 given depth in that water. He is able to determine directly and quickly 

 under the Microscope the actual condition of the water in relation to 

 organisms, organic and mineral detritus. 



Arctic Plankton.} — C. H. Ostenfeld gives an account of the marine 

 plankton from the east Greenland sea (west of 6° W. Long, and north of 

 73° 30' N. Lat.), collected during the ' Danmark ' Expedition of 1906-8. 

 He enumerates forty-two diatoms and six Flagellatae, one of which is 

 new, Pontosphsera borealis. 



Plankton of Prester See, near Magdeburg. — H. Honigmann§ 

 gives an account of the plankton of the Prester See, by Magdeburg, a 

 subject of which he has treated previously. || The plankton contains 

 Ohsetoceras, Acanthoceras, Oscillatoria, Genicularia, Tetraspora, Cltseto- 

 jieltis, Amphiprora, BaciUaria, etc. A bibliography of 264 papers is 

 appended. 



Vegetation of Upper Rhine.T — R. Lauterborn gives an account of 

 the vegetation of the Upper Rhine, the biological conditions of the 

 Rhine stream, the plankton, the so-called Altrheine, which accompanies 

 the river from Basel to Oppenheim, the biological characteristics of the 

 Upper Rhine. He also makes observations on several species of the 

 region of the Upper Rhine and Lake Constance. 



Plankton of Lago Maggiore.** — M. de Marchi publishes an intro- 

 duction to the biological study of the Yerbano or north end of Lago 

 Maggiore, in which he shows how much preparatory work has been 

 already done, and what lacunae remain in the study of Lago Maggiore. 

 He gives a systematic enumeration of the species, with the names of the 

 authorities for their existence in the Yerbano. 



* Die Ceratien. Leipzig : Klinkhardt (1911) 124 pp. (10 pis.). 



t Ber. Deutsch. Bot. Gesell., xxix. (1911) pp. 386-402. 



J Danrnark-Exped. til Groenlands Nordostkyst., 1906-8, iii. n. 11 (Kobenbavn, 

 1910). 



§ Abh. Ber. Mus. Natur. Magdeburg, ii. (1910) pp. 1-39 (1 pi.). See also Nuov. 

 Notar., xxii. (1911) pp. 95-96. 



|| Arcb. Hydrobiol. u. Planktonk., v. (1908) pp. 71-8 (2 pis. and figs.). 



! Verb. Nat. Med. Verein Heidelberg, x. (1910) pp. 450-502 (figs.). 

 ** Rendiconti R. 1st. Lombard., xliii. (1910) pp. 698-719. See also Nuov. Notar., 

 xxii. (1911) p. 99. 



