342 Algae. — Eumycetes. 



Guinea-current, situated between the two others, the Guinea-current 

 is characterised b}^ the occurrence otf a nuraber of organisms which 

 attain a greater frequency only in the shore-waters {Oikopleura 

 dioica, Proroceiitrum tnicans, Euglena). Especially remarkable was 

 the frequency of Euglena, which culminated in a depth of 50 — 75 m. 

 The north-tropics are divided into the Sargasso-Sea, signalised 

 by Sargassum, and into the Northequatorial current. The region 

 immediately south of the Azores (öth -loth June) also characterised 

 itself by its abundance in planis as well as by its temperature 

 as a region of transition from the cool water to the tropics. 

 In the Sargasso-Sea a progressive increase of the number of 

 the Coccolithophorideae was noticed as the ship approached the 

 centre of the Halostase. At its east-border (14 ~ 19 of June) Calyptro- 

 sphaera ohlonga occurred so frequently and Pontosphaera Huxleyi so 

 rarely, that the first species became the predominating form among 

 the Comllineae, an incident, which was during the whole voyage 

 only noticed at this place. During the expedition of the „Michael 

 Sars" Gran has made the same Observation at the north-border of 

 the Sargasso-Sea. In the N.Equatorial current Trichodesmium 

 became very frequent, and that kept on even in the Guinea current. 

 On entering the S.-Equatorial current (Aug. 19)untilnow thefollowing 

 species were found: Coccoltthophora leptopora and C.fragilis. In the Bra- 

 zil-curreni there appeared a number of other new forms, Brenneckella 

 kohlt and lorensoni, two Coscinodiscus with a swimmingbelt which 

 is constructed by Coccolithophorids and Michaelsarsia falklandica,dL 

 Coccolithoporid with radiate calcareous bristles round the mouth 

 of its Shell. The vertical distribution of the Microplankton in the 

 tropics is quite generally characterised by the greatest abundance 

 of plants not being on the average at the surface but at a depth of 

 50 m. Many CoccolÜhophoridae , show special adaptations for Suspen- 

 sion in the water. The most simple method consists in enlarging 

 the Shell far above the circuit of the cell {Cocc. fragüis). More com- 

 plicated adaptadons are those which are attained by developing 

 calcareous processus of many forms, and which appear as cups 

 {Scyphosphaera apteini Lohm.), as solid staff like appendices (Syraco- 

 sphaera pulchra spinosa) and as hollow, staff-like or trumpet-like 

 Processus [Rhabdosphaera, Discosphaera) or as radii round the mouth, 

 each of which is formed by a great number of joined Coccoliths 

 {^Michaelsarsia and Ophiaster). In the forms of the dusk-zone these 

 planctonic processus are limited to the cell-equator, so that they 

 cause at the same time a fixed orientation of the cell in the water, 

 by which the surfaces without processus are turned towards the 

 light {Scyph. apteini, Deutschlandia anthos Lohm.). Two stränge 

 groups of organisms {Halopappus and Acanthoica) show distinct 

 affinity to the Coccolithophoridae . Among the Diatomeae, Brenneckella 

 is remarkable for its symbiosis with Coccolithophoridae and among 

 the Protozoa Dictyocysta coccolitholega as well as Rhynchomonas. 

 The first one, a Ciliate, Covers its shell of chitinous matter with 

 Coccoliths, and the Flagellate Rhynchomonas occurs in three diffe- 

 rent forms in the north region of cool water, in the tropics and in 

 the south region of cool water. Matouschek (Wien). 



Knechtet, W. K., Pythium de Baryanum Hesse ca provocator 

 al unei boale de rasad de tutun. (Supliment la Buletinul 



