TOUR MALI A TRIGONELLA. 



811 



brown colour ; the length a foot and a half; and the 

 native habitat Southern Africa. This is the species 

 which approaches most nearly in its characters to the 

 Gallinidce. 



TOURMALIN. A mineral that has the sin- 

 gular property of displaying distinct electrical phe- 

 nomena by a mere change of temperature. This 

 mineral was known to the ancients, who called it 

 Lyncunum. Both Tourmalin and Schorl, with which 

 it is associated, occur in prismatic crystals of a dark 

 colour. This mineral generally occurs resting in 

 beds, or single strata, and is found in every quarter 

 of the globe. 



TOURNEFORTIA (Linnaeus). A genus of ever- 

 green shrubs, natives of the East and West Indies. 

 The flowers are pentandrous, and belong to Bora- 

 ginece. In the greenhouse they ripen seeds, by which 

 they are increased. 



TRADESCANTIA (Linnceus). Arather numerous 

 genus of herbaceous perennials, many of which are 

 ornamental. In English lists they are called spider- 

 'wort, from the irregular shape of the flowers and 

 their appendages. They belong to Hexandrin, and 

 to the natural order CommcliacccE. Open borders ; 

 division. 



TRAGIU^I (Springell). A genus of annuals, bien- 

 nials, and perennials, all herbaceous. They stand in 

 the fifth class of Linnaeus, and in the natural order 

 Umbelliferce. T. anisum is the valued anise, so much 

 cultivated in warm countries as a condiment, and for 

 its medicinal qualities. 



TRAGOPOGON (Linnaeus). A genus of her- 

 baceous biennials, chiefly natives of Europe, and com- 

 monly called goatsbeard. They bear large composite 

 flowers, and their seeds have feathery appendages ; 

 hence their name. The T. porrifolius is cultivated 

 for its spindle-shaped root as a culinary vegetable, 

 under the name of salsify. 



TRAPA (LinntEus). Is a genus called in English 

 water-caltrops ; found in India and in various parts 

 of Europe. The flowers are tetrandrous, and the 

 genus belongs to Hydrocharidece. T. natans is a Eu- 

 ropean plant. Some of the canals at Versailles are 

 covered with it, and the fruit is collected and eaten 

 as chestnuts. They are called jesuits'-nuts afVenice ; 

 and in some places they are called galarin, and much 

 eaten by the inhabitants. T. bicornis are common in 

 China, and form a common ingredient in stews, &c. 

 T. biapinosa are esteemed by the Hindoos. 



TRECHUS (Clairville). A genus of small cole- 

 opterous insects, belonging to the family CarabidcE, 

 and sub-family Harpalides, from which it is distin- 

 guished by having the terminal joint of the palpi 

 acute and conical, but longer than the preceding 

 joint ; the body is oval and sub-convex, and the pos- 

 terior angles of the thorax are rounded. They are 

 generally found at the roots of grass by the sides of 

 ponds or dam-banks. There are about a dozen 

 British species. 



TREMANDRE^E. A natural order of plants 

 containing only the genus Tetrathica, of which there 

 are seven species. They are all small bushes bearing 

 octandrous flowers, with foliage particularly neat and 

 resembling some of the heaths. They are greenhouse 

 plants, and are easily propagated by cuttings. 



TREVIRANA(Willdenow). A single but highly 

 ornamental plant, a native of Jamaica. The scarlet 

 flowers are didynamous, and belong to Scrophularinece. 

 This plant was called Achimedes cocdnea by Persoon, 



and Cyrilla pulchelln by others ; it affects sandy loam 

 and heath-mould mixed, in which it grows freely. 

 When the flowering is over, the pots should be kept dry ; 

 and against the growing season, according to Sweet, 

 the root should be divided and repotted, to ensure a 

 fine bloom. 



TRICHILIA (Linnseus). A genus of West India 

 trees, having decandrous flowers, and belonging to 

 the natural order Meliacece. In our collections they 

 are treated like other stove plants, and are increased 

 by cuttings of the half-ripened wood. 



TRICHIOSOMA (Leach). A genus, or rather 

 sub-genus of Tenthredinidous insects, separated by 

 Dr. Leach from the genus Cimbe.v (which see), but not 

 adopted by continental authors. The species are 

 distinguished by their hairy bodies, and by the four 

 hind femora being toothed. There are nine British 

 species. Type Tenthredo lucorum, Linnaeus. 



TRICHIUS (Fabricius). A genus of handsome 

 coleopterous insects, belonging to the family Ceto- 

 niid<z, and separated from the great Linnajan genus 

 ScarabcBus. See CETONIID^:. 



TRICHODIUM (Michaux). A genus of European 

 and American triandrous flowering plants, belonging 

 to Graminece. Two of them are found in Britain, viz., 

 T. caninum and T. cetaceum ; and the T. deciimbem is 

 cultivated in America. 



TRICHOPTERA (Kirby). An order of insects 

 established for the reception of the Linnoaan genus 

 Phryganea, and characterised by Mr. Kirby as fol- 

 lows : " Metamorphosis incomplete, mouth emandi- 

 bulate, prothorax replaced by a collar ; wings four, 

 upper pair mostly hairy, lower ample, folded ; neti- 

 ration branching ; anus without seta? ; eggs extruded 

 in a gelatinous mass." (Introd. to Ent. iv., p. 380). 

 Mr. MacLeay, in the Horas Entomologies, united 

 the Tenthrcdinidce with this order. By the French 

 authors the Phryganece are placed at the end of the 

 Nemoptera as part of that order. 



We have already given, in the article PHRYGANEA, 

 various details relative to the structure, habits, and 

 classification of these insects, which renders it unne- 

 cessary to enter more fully into these matters in this 

 place. 



TRIDENTE.E (Haworth). A genus of under- 

 shrubs, natives of the Cape of Good Hope, separated 

 from Stapilia by the late Mr. Haworth. The flowers 

 belong to Pentandria, and to the natural order Ascle- 

 piadece. Like other succulent plants/they require but 

 little water, and should be planted in light porous soil. 



TR1ENTALIS (Linnasus).: A genus of two little 

 herbs, one of which is a native of Britain, and called 

 winter-green. The flowers are heptandrous, and the 

 plants belong to Primulaccce. In the flower garden 

 they are planted in loose soil, and increased by seeds. 



TRIFOLIUM (Tournefort). A very extensive 

 genus of herbaceous annuals, biennials, and peren- 

 nials, commonly called trefoil, or clover. The flowers 

 are diadelphous, and belong to Leguminosce. They 

 are mostly European, and all more or less pasture 

 plants ; a few of them are particularly valuable to the 

 farmer, their introduction into agriculture having ad- 

 vanced the profits of that business, perhaps more 

 than any other cultivated plant. 



TRIGLOCHIN (Linnaeus). A genus of rushes 

 found in bogs in various parts of the world, and be- 

 longing to the order Jnncaginece. All are curious, and 

 some of them economical, for mat-making, &c. 



TRIGONELLA (Linmeus). A genus of herbs, 



