. The microscope and its revelations. cillar,and the breadth of the valves is usually (though not always) greaterthan the front view. The distinctive character of the genusXnr!rell(t, in addition to the presence of the supposed canaliculi,is derived from the longitudinal line down the centre of each valve(fig. 453, A) and the prolongation of the margins into ala?.Numerous species are known, which are mostly of a somewhat ovateform, some being broader and others narrower than >S. constricta ;the greater part of them are inhabitants of fresh or brackish water,though some few are marine ; and
. The microscope and its revelations. cillar,and the breadth of the valves is usually (though not always) greaterthan the front view. The distinctive character of the genusXnr!rell(t, in addition to the presence of the supposed canaliculi,is derived from the longitudinal line down the centre of each valve(fig. 453, A) and the prolongation of the margins into ala?.Numerous species are known, which are mostly of a somewhat ovateform, some being broader and others narrower than >S. constricta ;the greater part of them are inhabitants of fresh or brackish water,though some few are marine ; and several occur in those infusorialearths which seem to have been deposited at the bottoms of ;ueli as that of the Mourne Mountains in Ireland (fig. 468, b, c. /•).In I he genus Campylodiscus (fig. 454) the valves are so greatlyincreased in breadth as to present- almost the form of discs (A), andat the same time have more or less of a peculiar twist or saddle-shaped curvature (B). It is, in this genus that the supposed cana-.
Size: 1349px × 1852px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectmicrosc, bookyear1901
