ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 201 



Phytoplankton of Victoria Nyanza.* — 0. H. Ostenfeld reports on 

 some samples of plankton taken from the Victoria Nyanza, sent to him 

 by Agassiz. The interest of the collection lies in the fact that it was 

 made in the month of February, and can be compared with the plankton 

 of April, October, and November, already known from that lake. In 

 February Melosira Agassizii predominates with other diatoms of less im- 

 portance, while green aud blue-green algae are rare ; in April the green 

 algffi predominate, as well as Desmids and Protococcoideas, while diatoms 

 are of less importance and blue-green algre are rare ; in October and 

 November the Myxophyceas predominate, the green algas (especially 

 Botryococcus Braiinii) are subdominant as well as diatoms {Melosira 

 nyassensis and Surirellse), and the phytoplankton is very rich in species 

 and individuals. In the second chapter the author enumerates the species 

 observed in the collection entrusted to him, including 1 Peridiniale, 

 7 Bacillariales, 6 Myxophyceae, and 15 Chlorophyceae. Critical remarks 

 are made, and Melosira Agassizii is described as new. 



Swiss Plankton. f—C. H. Ostenfeld publishes notes on the tem- 

 perature of the water, time of gathering, and contents of some samples 

 of plankton from fifteen Swiss lakes. 



Desmids .|— L. Viret gives a list of Desniidiacese from the valley of 

 Trient in Canton Valais, Switzerland. The plants were collected at 

 stations which offered very different biological conditions, and the species 

 sixty-nine in number, include twelve novelties. The author finds that 

 Desmidiaceas are rare in clear water, such as torrents or brooks, 

 but are abundant in muddy water containing large quantities of humic 

 matter. Critical notes are appended. 



Devonshire Diatoms. §— J. B. Bessell mentions several interesting 

 diatoms found by him last summer in the neighbourhood of Torquay. 

 Among these are: — Achnanthidium flexellum Breb., Gomphonema intri- 

 catum Kiitz., Achnanthes coarctata Breb., and Navicula pusilla W. Sm., 

 at Anstey's Cove. Pinniilaria acrospheria Breb., P. subcapitata Greg., 

 Gomphonema subclavatum Grun., and Navicula elliptica of quite unusual 

 size, from Moretonhampstead. At Corbyn's Head several species were 

 found, which had been recorded by Griffiths more than fifty years ago ; 

 as well as Navicula inornata Grun., a new record. The most interest- 

 ing find was Syndendrium diadema Ehr., the spore form of Ghaeioceros, 

 probably brought by a current. 



The same author in another paper enumerates the Diatoinaceaa of 

 the Torquay district, which includes 203 species. 



Biddulphia sinensis in the North Sea.|| — C. H. Ostenfeld writes 

 once more on this subject, which has been treated at length by him. An 

 abstract of his work has appeared in this Journal,!!" and the present paper 



* Bull. Mus. Comp. Zool. Harvard College, iii. (1909) pp. 171-87. 

 t Ber. Schweiz. Bot. GeselL, xviii. (1908) pp. 6-13. 

 X Bull. Soc. Bot. Geneve, ser. 2, i. (1909) pp. 251-68 (1 pi.). 

 § Journ. Torquay Nat. Hist. Soc, i. (1909) pp. 13-14, and 26-33. 

 || Internat. Rev. Hydrobiog. and Hydrog., ii. (1909) pp. 362-74 (9 figs, in text). 

 4 See this Journal, 1910, p. 66. 

 April 20th, 1910 p 



