TUR 



TUR 



element which exists in the form of 

 tungstic acid in several minerals, the 

 most important of which are the native 

 tuiigstate of lime, also called scheelite ; 

 and the tungstate of manganese and 

 iron, also called wolfram. The tung- 

 state of lead, or seheel-lead ore, was 

 formerly confounded with the raolybdate 

 of this metal. 



TUNICA'TA {tunica, a tunic). The 

 first class of the moUusca, comprising 

 soft, aquatic, acephalous animals, having 

 their body enveloped in an elastic tunic, 

 furnished with at least two apertures. 

 They are distinguished into two orders, 

 viz. the Salparia, in which the forms are 

 organically united ; and the Ascidiaria, 

 which continue isolated by their external 

 tunic. 



TUPAFADiE. The Bangsrings ; a 

 family of insectivorous vertebrate ani- 

 mals, consisting of the single genus 

 tupaia. They are confined to the Indian 

 Archipelago, where, contrary to the usual 

 habits of the insectivora, they live in 

 trees, which they ascend with the agility 

 of quadrumanous animals. 



TU'RBIDiE. Marine snails ; a family 

 of phytophagous gasteropods, which 

 breathe by gills, and often exhibit the 

 carnivorous structure of the zoophagous 

 division of gasteropods. The shell is 

 solid, but not perlaceous, spiral ; the 

 aperture entire, closed by an operculum. 



TURBFNiE. Winkles; a sub-family 

 of the TurbidcB, named from the typical 

 genus turbo ; these are all marine shells, 

 with a perfectly entire aperture. 



TU'RBINATED {turbo, a top). A 

 term applied to shells which have a spi- 

 ral or screw-form structure, as that of 

 the garden-snail. 



TURBINE'LLIDiE. Turnip-shells ; a 

 family of carnivorous gasteropods, in 

 which the base of the shell is straight 

 and lengthened, and the pillar strongly 

 plaited. The mantle of the animal is 

 never dilated, but is of ordinary dimen- 

 sions, and drawn back into the shell with 

 the animal. 



TURBINELLI'NiE. A sub-family of 

 the TurbinellidcB, or Turnip-shells, 

 named from the typical genus iurbinella, 

 and characterized by the great size, 

 weight, and smoothness of the shell, the 

 great length of the canal, and the gene- 

 rally papillary state of the spire. 



TURBI'NIDiE. A family of gas- 



tropodous mollusks, named from the 



genus turbo. According to Linnaeus, 



the animal is a limax or slug ; the shell 



350 



is univalve, spiral, solid ; the aperture 

 narrowed, orbiculate, entire. Lamarck 

 gives the name Turbinacea to the last 

 family of his herbivorous trachelipods ; 

 all are marine shells, appearing to be 

 provided with an operculum. 



TURDI'N^ {turdus, a thrush). Tur- 

 dine birds or thrushes ; a family of the 

 Cantatrices of Macgillivray, which have 

 a moderately rapid, somewhat undulated 

 flight, and on the ground advance by 

 leaping. Most of the species are re- 

 markable for their superiority of song. 



TURIO. The botanical term for a 

 scaly bud, developed from a perennial 

 subterranean root, as in asparagus. 



TURKEY-SLATE. Whet-slate; No- 

 vaculite. A massive greenish-grey mi- 

 neral, occurring in beds in primitive and 

 transition clay-slate. Very fine varieties 

 are brought from Turkey, called hone- 

 stones. It is used for sharpening steel 

 instruments. 



TU'RMERIC. The tuber of the cur- 

 cuma longa, which yields a beautiful 

 bright yellow colour. Turmeric paper is 

 unsized paper, brushed over with tincture 

 of turmeric, prepared by digesting one 

 part of bruised turmeric in six parts of 

 proof spirit. 



TURNBULL'S BLUE. Ferricyanide 

 of iron. A blue precipitate which is 

 thrown down when red prussiate of pot- 

 ash is added to a protosalt of tin. 



TU'RNERITE. A rare mineral, con- 

 taining alumina, lime, magnesia, and iron, 

 found only on Mount Sorel in Dauphiny. 



TURNER'S YELLOW. Cassel Yel- 

 low; Patent Yellow. An oxichloride of 

 lead. 



TURNSOLE. A deep purple dye ob- 

 tained from the crozophora tinctoria, an 

 euphorbiaceous plant. 



TURPETH MINERAL. The name 

 given by chemists to the sub-sulphate of 

 mercury. 



TURQUOIS. Calaite; Odontalite. An 

 opaque gem found chiefly at Nishapur, in 

 the province of Khorasan, in nodules or 

 as small veins traversing a ferrugino- 

 argillaceous rock, and greatly esteemed 

 on account of its beautiful blue colour, 

 which will in most cases be sufficient to 

 distinguish it both from the blue silicate 

 of copper, and from fossil bones (parti- 

 cularly teeth) impregnated with blue 

 phosphate of iron or carbonate of copper 

 — the occidental turquoises of lapida- 

 ries. 



TU'RRILITE. An extinct genus of 

 spiral, turreted, chambered shells, allied 



