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LOCOMO'TION. (from locus and motio, 

 Lat.) The power of moving at 

 will from one place to another ; of 

 transferring the whole body from 

 one place to another. The power 

 of locomotion constitutes the most 

 general and palpable feature of 

 distinction between animals and 

 vegetables. Excepting a few among 

 the lower order of creation, such 

 as molluscs and zoophytes, all 

 animals are gifted with the power 

 of spontaneously changing their 

 situation. 



LOCTTLI'CTDAL. In botany, a par- 

 ticular kind of dehiscence. Some 

 fruits open by the dividing of each 

 carpellum at its midrib, so that 

 the dissepiments stick together, 

 and to two halves of contiguous 

 carpella; this is called loculicidal 

 dehiscence. 



LODE. (a mining term.) A word 

 used to signify a regular vein or 

 course, whether metallic or not; 

 but most commonly it signifies a 

 metallic vein. When the substances 

 forming the lodes are reducible to 

 metal, the lodes are said to be 

 alive ; otherwise, they are termed 

 dead lobes. 



Loess. (Germ.) A provincial German 

 term for an alluvial tertiary de- 

 posit of calcareous loam, occurring 

 in detached patches throughout 

 the valley of the Rhine. In Alsace 

 the loess is termed lekm. It 

 encloses freshwater and land shells, 

 as well as some mammiferous 

 remains. Sir C. Lyell observes, 

 "the loess is found reposing on 

 every rock, from the granite near 

 Heidelberg to the gravel of the 

 plains of the Rhine. It overlies 

 almost all the volcanic products, 

 even those which have the most 

 modern aspect; and it has filled 

 up, in part, the crater of the 

 Rodenberg, at the bottom of which 

 a well was sunk in 1833, through 

 seventy feet of loess. 



LOLI'GO. (loligo, Lat.) A genus of 



the family of Sepise. In the loligo 

 is found that peculiar provision for 

 defence, the ink-bag, a bladder- 

 shaped sac, containing a black and 

 viscid ink, the ejection of which, 

 by rendering the surrounding 

 water dark and opaque, defends 

 the animal from the attacks of its 

 enemies. In the lias of Lyme 

 Regis, ink-bags of the fossil loligo 

 are preserved, still distended, as 

 when they formed parts of the 

 organization of living bodies, and 

 retaining the same juxta-position 

 to an internal rudimentary shell 

 resembling a horny pen, which the 

 ink-bag of the existing loligo bears 

 to the pen within the body of that 

 animal. 



LO'MONITE. Diatomous Geolite. So 

 named after its discoverer, Gillet 

 Laumont. See Laumonite. 



LONCHO'PTERIS MANTE'LLI. A species 

 of fossil fern found in the shales 

 and clays of Tilgate Forest, and 

 thus named after Dr. Mantell. It 

 is characterised, by the distribution 

 of the nervures of the leaves. 

 This fern probably did not exceed 

 a few feet in height. 



LONDON CLAY. (The name London 

 Clay has been assigned to this 

 great argillaceous formation from 

 the circumstance of its forming 

 the general substratum of London 

 and its vicinity, occurring imme- 

 diately beneath the vegetable soil, 

 excepting when occasional deposits 

 of alluvial, or diluvial, gravel, sand, 

 &c., intervene.) This formation 

 consists of a bluish or blackish 

 clay, including, in some localities, 

 beds of grey limestone and sand- 

 stone, lying immediately over the 

 plastic clay and sand, and is an 

 upper member of the arenaceous 

 and argillaceous formation that 

 covers the chalk. Its thickness is 

 very considerable, sometimes ex- 

 ceeding 700 feet. It contains lay- 

 ers of ovate, or flattish masses of 

 argillaceous, limestone. These 



