I • SUMMARY OF CURRENT RESEARCHES RELATING TO 



Algaa of Tripoli.* — R. Muschler gives an enumeration of algae, 

 marine and fresh-water, recorded for Tripoli, Gyrenaica, Fizzan, etc., in 

 Dnrand and Barratfce's Libyan Flora. The number of species is eighty- 

 four. Distribution and synonymy are appended in each case. 



Algas of North Carolina. f — In a paper entitled " The Plant Life of 

 Ellis, Great, Little, and Long Lakes in North Carolina," W. 11. Brown 

 deals shortly with their algal flora. That of Lake Ellis is rich in both 

 species and individuals. The green algae are abundant, but not in good 

 condition in the summer season, while the blue-green algae are more 

 abundant and more vigorous. The blue-green seem to endure the high 

 and changeable temperature better than the green algae. The algal 

 flora of Great Lake is very scanty, and this is associated with an absence 

 of supporting plants, the darkness of the water, and the presence of 

 great quantities of bacteria. The phanerogams in Lake Ellis compete 

 with the algas for C0 2 and possibly also for mineral matter, and thus 

 probably tend to decrease the amount of phytoplankton, although the 

 mechanical support which they afford the algae may counterbalance the 

 effect of the competition to some extent. 



Diatoms and Flagellatse from East Greenland.^ — C. H. Ostenfeld 



gives a list of the Diatoms and Flagellates in the surface plankton col- 

 lected during the Danish Expedition to the North-east Coast of Greenland 

 in 1906-8. Forty-three species of diatoms are recorded and five Flagel- 

 lates. Novelties are Coscinodiscas Joergensii and a Coccolith, Pontosphsera 

 borealis. 



Periodicity of Phytoplankton of the Leopoldstein Lake.§ — K. v. 

 Keissler reports on the investigations concerning the periodicity of the 

 phytoplankton of the Leopoldsteiner See in Styria. From March to 

 September, 1910, Peridiniiim, Asterionella, Cyclotella, and Staurastrum 

 were the most important constituents. Geratium and Dinobryon were 

 wanting, as also Fragilaria, Synedra, and Botryococcus. The rarest 

 record is Asterionella formosa Hsskn. var. acaroides Lenim. Asterionella 

 and Peridiniiim cinctum were noticed in many different stages of division. 

 Hydrurus fretidus disappeared in warmer weather, and the gelatinous 

 1 tails of Ophrydium were taken possession of by diatoms. 



Halosphsera and Flagellatae. || — C. H. Ostenfeld publishes an 

 important report on the geographical distribution and biology of 

 Halosphsera viridis, Phseocystis Pouchetii Lagerh., P. globosa Scherf., 

 Dinobryon, divergens Imhof, D. pellucidum Levand., Coccolithophora pela- 

 gica Lohm., Distephanus speculum Haek., and Dictyocha fibula Ehrenb. 

 He deals also with their special distribution in the regions examined by 

 the Danish Expedition Some of the results are demonstrated by means 

 of maps. It is found that Halosphsera has its home in the warm Atlantic, 

 and is only carried north by the Gulf Stream. 



* Durand et Barratte, Flora? Libycse Prodromus. Geneve : Romet, 1910, pp- 

 203 L3. t Contrib. U.S. Nat. Herb., xiii. pt. 10 (1911) pp. 323-41. 



I Mcddel. om Greenland, xliii. (1910) pp. 259-85 (11 figs.). 



§ Anzeig. k. Akad. Wiss. Wien, xlvii. (1910) pp. 371-3. 



I Conseil Perm. Intermit Explor. de la Mer : Bull, trimest. Resume Plau- 

 tonkpie, i. (Copeubague, 1910) pp. 20-38 (pi. 3-5). 



