TEG 



[428] 



T E M 



or arrangement of animals or plants, 

 according to certain principles, in 

 divisions and groups. 



TE'GMEN-. (tegmen, any sort of cover- 

 ing, Lat.) A covering of the body, 

 as the cuticle, &c. : used in botany 

 to denote one of the coats of the 

 seed; in entomology, applied to 

 the coverings of the wings of the 

 order Orthoptera, or straight- winged 

 insects. 



TELEOSA'URTTS. A genus of fossil sau- 

 rians, thus named and arranged by 

 M. Geoffroy St. Hilaire. The tele- 

 osauri have long and narrow beaks, 

 the nostrils forming almost a ver- 

 tical section of the anterior extre- 

 mity of the beak. " One of the 

 finest specimens of fossil teleosauri 

 yet discovered was found in the year 

 1824, in the alum shale of the lias 

 formation at Saltwick, near Whitby ; 

 its entire length is about 18 feet, the 

 head one foot in breadth, the snout 

 was long and slender, as in the 

 gavial, the teeth one hundred and 

 forty in number. Some of the 

 ungual phalanges show that the 

 extremities were terminated by 

 long and sharp claws, adapted for 

 motion upon land, from which we 

 may infer that the animal was not 

 exclusively marine." 



TELEO'STI. The fourth order of the 

 class Pisces, comprising the perch, 

 cod, salmon, and other ordinary 

 osseous fishes. 



TELLI'NA. (tellina, Lat.) A genus 

 of orbicular, or ovate transverse, 

 equivalved, marine bivalves, with 

 a fold on the anterior part, and 

 short beaks, found in sands, at 

 depths varying to fifteen fathoms. 

 Hinge with usually three teeth, 

 the lateral ones smooth on one 

 side. The shells of this genus are 

 chiefly known by the inflection, or 

 irregular fold, on the fore part; in 

 the one valve the fold is convex, 

 in the other, concave. There are 

 three families of tellinaB : ovate and 

 thickish; ovate and compressed; 



suborbicular. Some conchologists 

 have divided Tellina into three 

 genera ; Tellina, Cyclas, and Pan- 

 dora. Many species of this genus 

 are found fossil. 



TELLI'NIDES. A genus of sub-equi- 

 valve, inequilateral, transverse, 

 marine bivalves, found in sandy 

 mud at depths varying from five to 

 fifteen fathoms. 



TE'LLINITE. A fossil tellina. 



TELLTJ'BIUM. The name given by 

 Klaproth to a metal first discovered 

 by him or by Miiller in 1 782, from 

 an ore of gold, with which metal it 

 is found combined in the Transyl- 

 vanian mines. Its colour is nearly 

 a tin white, with a shade of blue. 

 Structure foliated. Specific gra- 

 vity 6'1. Before the blow-pipe it 

 fuses easily, and is very volatile, 

 giving out a pungent odour, com- 

 pared by some to that of a radish. 

 Tellurium is not used in any form. 

 Symbols Te. 



NA'TIVE TELLT/RITTM. Rhombohedral 

 Tellurium. The tellure natif auro- 

 ferrifere of Haiiy ; gediegen silvan 

 of Werner; tellure natif ferrifere 

 of Brongniart. This ore is never 

 perfectly pure. It always contains 

 a greater or less quantity of gold, 

 and sometimes silver, lead, copper, 

 and sulphur. It is found in Tran- 

 sylvania only, in veins, traversing 

 grey wacke. It is of a white colour ; 

 of a shining and metallic lustre; 

 brittle and frangible. Its constitu- 

 ents are tellurium 92 '6, iron 7% 

 gold 0-2. 



TE'MPERATUEE. (temperatura ) 'L^t. tem- 

 perature, Fr. temperatura, It.) Con- 

 stitution of nature; the constitution 

 or state of the atmosphere, whether 

 it be hot or cold, humid or dry ; 

 the condition of a body, as mani- 

 fested by its influence on the ther- 

 mometer. 



A question of great importance, 

 in the study of geology, arises as 

 regards the existing and the former 

 temperature of this planet. Whether 



