ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 675 



systematic position ; V. the classification ; VI. the distribution, occur- 

 rence, and significance, including the author's methods of capture, preser- 

 vation, and examination. 



This author regards Coccospheres as true Flagellata?, probably 

 forming a family in the division Chrysomonadina. He shows that the 

 name Coccosphaera must be dropped as having been previously used tor 

 another organism ; and he therefore proposes instead the name Coccolitho- 

 phora. His method of capture of these minute bodies is most ingenious. 

 Hitherto nets have been used of the finest silk gauze, but Lohmann 

 catches them by means of the filteriug apparatus of species of Appendi- 

 cularia which feed on them. An examination of the carefully constructed 

 apparatus provided by nature in these organisms has revealed a large 

 number of species of Coccolithophoridae which were small enough to slip 

 through the finest meshes of a net, and the author has thereby been able 

 to form satisfactory estimates as to their distribution and occurrence. It 

 has also been possible to study their minute structure in a manner un- 

 known before, and the results are given in section II. The work was 

 carried on in the Mediterranean, and the author shows that these 

 organisms are much more common in the upper layers of the sea than 

 had been supposed. As regards tbe systematic treatment, the author 

 divides them into two main groups: Syracosphserinse having unper- 

 forated Coccoliths, and Coccolithophoringe with perforated Coccoliths. 

 Five new genera are described and seventeen new species. 



Plankton of Alpine Lakes.* — Carl v. Keissler has continued his 

 investigations on the plankton of the Aber- or Wolfgang-See in Salz- 

 burg. The author gives a list of both the phyto- and zoo-plankton met 

 with in the lake from June to September. The Chlorophyceae number 

 five, among which Botryococcus Braunii Kutz. is described in some detail 

 with the aid of a plate ; the diatoms number fourteen ; the Schizophyceae 

 present include four forms, among which a new variety GJiroococcus minor 

 Naeg. var. dispersus is described and figured as a new variety ; the phyto- 

 plankton further includes three PeridineaB and six Flagellata. Of the 

 zoo-plankton, two Protozoa, five Rotatoria and six Crustacea are men- 

 tioned. Tables are given, indicating the relative number of the forms 

 at various times of the year, and also comparing the plankton of this 

 lake with that of two other Alpine lakes, the Neuenbcrger See and the 

 Ottersee, for the months of August and September. Tables are also 

 provided to show the vertical distribution of the various orgunisms, and 

 aiso the total quantity of plankton present at various depths. 



Pond Plankton.f — In May 1898 a pond in the palm-garden at 

 Frankfort a. M. was seen to be coloured a deep green, and Otto Zacharias 

 found that this was caused by the excessive multiplication of a desmid, 

 Polyedrium papilliferum var. tetragona Br. Schroder. The cells were 

 12 jx long and about the same breadth, except at the girdle where they 

 measured 8 /a. There was also with it a small quantity of Scenedesmus 

 opoliensis Kicht. and Synedra delicatissima W. Sm. In July of the 

 same year the author found a similar luxuriant growth of coenobia of 

 Pediastrum boryanum, which gave a light green colour to the water of a 



* "Verhandl. k. k. zool.-bot. Gesell. Wien, lii. pp. 305-27 (1 pi. and 1 text fig.). 

 t Biol. Centrsflbl., xxii. (1902) pp. 535-6. 



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