G{) NOTES ON THE AGRICULTURE, BOTANY 



Scenedesemus, Trachelomonas volvocina, and T. hispida. 

 But with the gradual growth of the rice plants and with the 

 shading of water and also by the frequently drying up of the 

 water in rice fields many plants and algae began to disappear, 

 others at first collect on the wet slime and after that on more 

 firm ground. 



The flora of algae in rice fields, lying in the running 

 water is characterised by the presence of many attached dia- 

 toms, sometimes making a compact layer over the surface 

 of the plants. Other rice fields are very rich in different 

 conjugatae kinds of Oedogonium; and other forms — signs of 

 more clean stagnant water. 



XI. — The Phytoplankton of some Tibetan Lakes. 



The present small note represents the result of the 

 observation of a collection gathered by Mr. Ladigin during 

 the expedition in Tibet in 1901 and all the samples were 

 examined by me in the Petrograd Academy of Science. 



The plankton taken from the freshwater lake Kur^k-nor 

 (i,vi, 1901) in the Tsaidam district contains a rich zooplaftkton, 

 in which were seen Ceratium hirundinella (0. F. M). Schrank 

 and also non-planktonic algae as Pinnularia gentilio Donkin, 

 Epithemia turgida (Erenb.) Kutz. and Lyngbya aestuarii 

 (Mert.) Lieb. 



In the bottle from the salt lake Toso-nor (3, vii, 1901), 

 which is not far from lake Kukunor, in a rich zooplankton, 

 were seen only few specimens of Oocystis Jacustris and 

 Synedra acus Kutz. 



The most interesting was the plankton from the lake 

 Khara-nor in which were found the following species : 



Melosira islandica O. Mull. Lyngbya limnetica. Lemm. 



subsp. helvetica 0. Mull. Pediastrum Boryanum (Turp.) 



Fragilaria crotonensis Kutton. Menegh. var. granulatum 



Aphanothece stagnina (Spren.) (Kutz) A. Br. 



A. Br. P. duplex Meyen. var. asperum 



Chroococcus limneticus Lemm. A. Br. 



Microcystis flos aquae (Wittr.) Botryococcus Braunii Kutz. 



Kirch. Cosmarium Botrytis Menegh. 



M. elabens (Menegh.) Kutz. Gloetila Scopulina (Haz.) Heer- 



M. incerta. Lemm. ing. 

 M. holsatika. Lemm. 



XII. — On some Freshwater Algae Collected 

 in Shanghai. 



Being in Shanghai in June 1918 a small collection of 

 Algae was gathered by me in a pond near the Public Gardens. 



