. The Annals and magazine of natural history; zoology, botany, and geology. Natural history; Zoology; Botany; Geology. 394 On the Flint Nodules of the Trimmingham Chalk. siliceous casts of Foraminifera, after the following observa- tions by Carter. In a letter, dated June 16, 1875, he writes, " . . the dumb-bell form you pointed out to me has almost close to it the original kind of test (silicified) from which it appears to have come, thus :—. "Correctly drawn to the same scale, viz. -^j- to T-^z inch. " A is the dumb-bell or cast of the chambers (e) of the Organism; a, the cast
. The Annals and magazine of natural history; zoology, botany, and geology. Natural history; Zoology; Botany; Geology. 394 On the Flint Nodules of the Trimmingham Chalk. siliceous casts of Foraminifera, after the following observa- tions by Carter. In a letter, dated June 16, 1875, he writes, " . . the dumb-bell form you pointed out to me has almost close to it the original kind of test (silicified) from which it appears to have come, thus :—. "Correctly drawn to the same scale, viz. -^j- to T-^z inch. " A is the dumb-bell or cast of the chambers (e) of the Organism; a, the cast of the tube which connected the chambers. " B is the silicified foraminifer, b the test, c c the chambers. A little tube seems to have been prolonged from one chamber (d), and may have been connected with another chamber or cast. Thus the dumb-bell is a cast of a couple of chambers of a Foraminifer connected by the intervening ;] In concluding this description of the various kinds of spicules I would add that in the majority of cases I regard the identifications and generic groupings proposed as provi- sional only. It is with many misgivings that I have made many of them ; and nothing but the fact that I had under- taken the task of classification would have induced me to continue what I have felt at times to be a hopeless endeavour. Some kind of order, however, has been evolved out of chaos, though probably not that which wculd result if, by any process of magic, the spicules could be restored to their proper places in the structure of their original owners. Many forms of spicules remain undescribed; those here represented have been derived from two or three small flints only. Of the rich sediments which remain from some twenty or thirty other specimens I have made no use in this paper; they remain for future observation, and are at the disposal of any one who would care to examine them. Mineral Condition of the Spicules.—The spicules are white and opaque w
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