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Show G2 GlOSSARY. AMMONITE. An extinct and very numerous genus of the onler of molluscous animals, called Cephalopoda, allied to the modern genus Nautilus, which inhabited a chambered shell, curved like a coiled snake. Species of it are found in all geological periods of the secondary strata ; but they have not yet been seen in the tertiary beds. They are named from their resem. blance to the horns on the statues of Jupiter Ammon. AMORI'HOUS. Bodies devoid of regular form. Etym., a, a, with. out, and p.op¢11. morphe, form. AMYGDALom. One of the forms of the Trap-rocks, in which agates and simple minerals appear to be scattered like almonds in a cake. Etym., aftvyoaX.a, amygdala, an almond. ANALCI!IfE. A simple mineral of the Zeolite family, of frequent occurrence in the trap-rocks. ANALOGUE. A body that resembles or corresponds with another body. A recent shell of the same species as a fossil-shell, is the analogue of the latter. ANoPLOTHEltE, ANoPLOTHERIUM. A fossil extinct quadruped belonging to the order Pachydermata, resembling a. pig. It has received its name because the animal must lmve been singularly wanting in means of defence, from the form of its teeth and the absence of claws, hoofs, and horns. Etym., ayo7rAor;, anoplos, unarmed, and 811pwv, therion, a wild beast. ANTAGONIST PowERs. Two powers in nature, the action of the one counteracting that of the other, by which a kind of equilibrium or balance is maintained, and the destructive effect prevented that would be produced by one operating without a check. ANTENN.IE. The articulated horns with which the heads of insects arc invariably furnished. ANTHRACITE. A sl1ining substance like black-lead; a species of mineral charcoal. Etym., ayfJpa~, anthrax, coal. ANTHRACOTHERIUM. A name given to an extinct quadruped, supposed to belong to the Pachydermata, the bones of which were found in lignite and coal of tl1e tertiary strata. Etym., aP8pa~, ant/wax, coal, and 8YJptoJI, therion. wild beast. ANTIIROPOMORPHOUS. Having a form resembling the human. Etym., ayfJpw7rot, anthropos, a man, and p.opcpT/, morphe, form. ANTICLINAL Ax1s. If a range of hills, or a valley, be com-posed of strata, which on the two sides dip in opposite directions, the imaginary line that lies between them, towards which the strata. on each side rise, is called tbe anticlinal axis. In a row of houses with steep roofs facing the south, the slates represent inclined strata dipping north and. south, and the ridge is an east GLOSSARY. G3 and west anticlinal axis F t gram, see vol. iii. p. 29a. or a artlier explanation, with a dia- ANTISEPTzc. Substances whi h . . veO'etable matter c prevent corruption In animal and Et;m '.as common salt does, are said to be antiseptic ., ayn, agaznst, and UYJ7rw, sepo, to putrefy. . ARENACEous. Sandy. Etym. , A rena, san d. · AnaiLLACEous. Clayey, composed of cia E . AnnAGONITE. A simple rnineral a va . ty. f tybm., Argzlla, clay. I fi . ' rie Y o car onate of lim ca led rom havmg been first found i A . . e, so A A . I . n rragon, In Spam uarfiTE. tump _e m111eral of a dark green, or black colour· which orms a constituent part of many varieties f 1 . ' A M . o vo came rocks. VALANCHES. asses of snow whiCh being d t 1 d f h . h . I AI ' e ac Ie rorn great eig ts 111 t le ps, acquire enormous bulk b c. h • · h d Y tres accumula-tions as t ey escend; and when they fall int th 11 b r. o e va eys elow 01ten cause great destruction. They are als Il d l d l h . . o ca e avanges an avanc es, 111 the d1alects of Switzerland. ' BASA.L T. One of the most common varieties of th e T rap-roc k s It IS a dark green or black stone composed of au "t d c. I. • ' ~eM ~~u very co.m pact In t.e xture, and of considerable }1 ar dn ess, o f ten' found 111 regular pillars of three or more sides, called basaltic columns. Ve.r y r,e ma, rkable examples of this k1· n d of roc k are seen at the G1ant s Causeway in Ireland and at p· l' c . . ' , mga s ave m the Island of Staffa, one of the Hebrides. The ter · d b ' Pl . d . . . m Is use y ·rm ·y , a·n Is said, to. come from basal• an .lEthiopi an wor<1 s,·i g-m, ymg non., not an Im.p robable derivation • inasmuch as tl 1e roc1" often ~ontams much Iron, and as many of the figures of the Egyptian temples are formed of basalt. ' BAsiN' of Paris, ' BAsiN' of London. Deposits lying in a great h.o llow or t.r ough surrounded by low hills or hi'gh 1a n d, some-times used 111 ge~logy almost synonymously with ' formation.' BELEMNITE. An extmct genus of the order of molluscous animals called Cephalopoda, tlmt inhabited a long, straight, and cham· bered conical shell. Etym., {3EAEJ1.YOJI, belemnon a dart BITUMEN. Mineral pitch, of which the tar-like sub;tance ~vhich is often seen to ooze out of the Newcastle coal when on th fi d h. h . e re, an• 1w 1c makes 1t cake, is a good example. Efym ., B't tu men, pttc 1. BITU~INous SHA~E .. An argillaceous shale, much impregnated with b1tumen, wh1ch IS very common in the coal measures. BLENDE. A metallic ore, a compound of the metal zinc with sui~ phur. It is often found in brown shinin~ crystals, hence its name among the German miners, from the word blenden to dazzle. ' |