CALAMITES, (Gk. KaXakdrns, hula in it (R, reed-like, from sciXakLos, kalomos, reed). A genus of fossil plants, appearing first in the Devonian rocks, and rising through the intermediate formations to the Jurassic, where it is represented by a single species. They reach their maximum development in the coal-meas ures, where a large number of species have been determined. The tall. straight stems nice from a swampy clay soil in profusion in the forests of sigillaria, and formed a striking and characteristic feature of the coal flora, though they supplied little material for the structure of coat. They are hollow-jointed cylinders, with longitudinal furrows, giving the fossil the ap pearance of equiseta. From this resemblance. botanists have generally considered as huge 'horse-tails.' They belong to the equiseta, and the study of many specimens. both macroscop ically and microscopically, has developed a number of sub-genera. The modern 'horse-tail rush' represents, according to Seward. a degen erate type of the yvatanitean group. Hooker was tunable to detect any traces of structure, in carefully prepared specimens, or the presence of those siliceous which characterize equiseta, and which should have been preserved in the fossil state; but later investigators have been more sueeessful in finding specimens from which internal structures could be determined.
Fleming has shown that the furrows are mark nig'. on Me interior cavity. The lower portion of a calamites trunk would show rings of scars where branches had fallen off, while higher up the younger branches contained whorls of slen der leaves and long, slender cones. The root termination was conical, the joints increasing upward in size and length. The foliage of eala mites has been deserib;;c1 under different names. A sterophylliles include,: jointed and fluted stems, with branches proceeding front the joints, and bearing long, pointed leaves. A onularia has closely arranged leaves, while in the leaves were wedge-shaped. See Com.; CAR BONIFEROUS SYSTEM.