. The depths of the ocean; a general account of the modern science of oceanography based largely on the scientific researches of the Norwegian steamer Michael Sars in the North Atlantic. Oceanography. DEPTHS OF THE OCEAN Naked flagellates. wreath. Calciosolenia murrayi resembles, to some extent, the shape and structure of Rhizosolenia, as the shields of lime are not rounded like those of most other species, but rhomboid and spirally bent, so that between them they form a cylindrical tube, pointed at either end, and furnished at the extremities with one or two fine calcareous setae. • Notwithst
. The depths of the ocean; a general account of the modern science of oceanography based largely on the scientific researches of the Norwegian steamer Michael Sars in the North Atlantic. Oceanography. DEPTHS OF THE OCEAN Naked flagellates. wreath. Calciosolenia murrayi resembles, to some extent, the shape and structure of Rhizosolenia, as the shields of lime are not rounded like those of most other species, but rhomboid and spirally bent, so that between them they form a cylindrical tube, pointed at either end, and furnished at the extremities with one or two fine calcareous setae. • Notwithstanding their small dimensions these microscopic calcareous algae oc- AJv^\ \ \ cupy a very important place in the economy of the sea, and their shields of lime, which may be met with in geological deposits dating from as far back as the Cambrian period, show that they have retained their shape practically un- altered through im- measurable ages. They are almost en- tirely oceanic, and mostly belong to the warmer seas. In coastal waters, where the salinity is lower, they are scarcer, but the commonest species, the little Pontosphczra huxleyi, has been found even in the Baltic, and there were such immense quantities of it in the inner parts of the Christiania fjord during the hot summer of 1911 (5 to 6 million cells per litre) that the calcareous cells with their strong refraction gave the sea quite a milky appearance. The naked flagellates in the sea are still only imperfectly known, though, no doubt, the part they play is quite a consider- able one. In coastal waters they occur sometimes in such abundance that we have actually been able, even with our present defective methods, to discover and describe a number of species. In the open sea we are best acquainted with the passive and. Fig. 239.—Different Types of Coccolithophorid^. (ioToo). 1, Michaelsarsia elegans ; 2, Ophiaster formosus ; 3, Rhabdo sphcera claviger ; 4, Syracosphczra prolongata ; 5, tenia murrayi ; 6, 7, Co
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Keywords: ., bookcentury1900, bookdecade1910, bookpublisherlondo, bookyear1912
