LAM 



[247] 



LAP 



nation are always meant layers of 



deposition. 

 LAMN'ODUS. A genus of ichthyolites 



of the old red sandstone formation, 



called also Dendrodus, (but which 



latter has been supplanted,) of 



which three species have been 



described by Agassiz. 

 LA'NATE. | (from lanatus, Lat.) 

 LA'NATED. j Woolly; covered with 



a sort of pubescence resembling 



short woolly hairs. 

 LA'NCEOLATE. Lance-shaped ; narrow 



and tapering. 



1. In conchology, applied to a 

 shell of an oblong shape, and 

 gradually tapering at each end. 



2. In entomology, in describing 

 the figure of the superficies, when 

 the base is not so broad as the 

 centre, and the lateral margins 

 slightly, but equally swollen, 

 gradually tapering towards the 

 apex, where it terminates in a 

 point, and the longitudinal diameter 

 more than three times the length 

 of the transverse. Burmeister. 



3. In botany, applied to leaves of 

 a narrow oblong form, gradually 

 tapering towards each end. 



LA'NCIFORM. (from lancea and/on/^, 

 Lat.) Spear-shaped; lance-shaped. 



LA'NDSLIP. A portion of land that 

 has separated from the main body, 

 in consequence of long- continued 

 rains, or the expansive powers of 

 severe frosts, and has fallen to a 

 lower situation. Landslips must 

 necessarily be often attended by 

 fatal consequences, as in the falls 

 of avalanches. We are informed 

 that when the mountain of Piz fell, 

 in 1772, three villages, with the 

 entire population, were covered ; 

 and that when part of Mount 

 Grenier, in Savoy, fell, in 1248, 

 five parishes were buried, the ruins 

 ocupying an extent of nine square 

 miles. 



LA'NGOUSTE. (Fr. sorte d?6crevisse de 

 mer.) The name given by the 

 French to the Palinurus vulgaris of 



Leach; the cray-fish or thorny 

 lobster. 



LA'NTANE. j (from \avdavuo, to con- 



LA'NTHANUM. ) ceal, Gr.) One of 

 the elementary bodies, its symbol 

 being La. 



LANU'GINOSE. | (from lanuginosus, 



LANT/GUNOUS. j Lat.) In entomo- 

 logy, when longish curled hair is 

 spread over the surface; covered 

 with soft hair resembling wool. 



LA'PIDES JTJDA'ICT. A name given to 

 certain fossil spines of echinites, 

 formerly supposed to be petrified 

 olives. 



LAPIDIFICA'TION. (lapidification, Fr. 

 from lapis, a stone, andyzo, to make 

 or become, Lat.) The conversion 

 into stone of some other substance ; 

 the act of forming stone. 



LAPI'LLI. (lapillus, Lat.) Volcanic 

 cinders, abounding in minute glo- 

 bular concretions. 



LA'PIS LA'ZULT. The Lazurstein of 

 Werner ; Azure-stone of Jameson ; 

 Lazulite of Haiiy ; Dodecaedrischer 

 Kuphon-spath of Mohs. When 

 lapis lazuli is pure, it is a mineral 

 of a fine azure-blue colour ; it 

 occurs in rhombohedral dodecahe- 

 drons, massive, and disseminated. 

 Structure finely granular, almost 

 compact ; fracture uneven or con- 

 choidal; lustre feeble; a little 

 translucent at its edges. It scratches 

 glass, but gives sparks with steel 

 with difficulty. Specific gravity 

 about 2*30. Its analysis is very 

 differently given by different auth- 

 ors. It contains silica, nearly 

 fifty per cent, carbonate of lime, 

 alumina, potash, soda, oxide of 

 iron, and sulphuric acid. It occurs 

 associated with primary rocks, es- 

 pecially granite. It is accompanied 

 by garnets, quartz, felspar, &c., 

 with some of which it is often 

 intermixed. It is found chiefly in 

 China, Persia, and Russia. It is 

 capable of a high polish, and is 

 much esteemed. Its chief use, 

 however, is to furnish the ultra- 



