TEE 



[430 ] 



TEE 



of the mouth, which have no arti- 

 culations; but, in a larger sense, the 

 term has been applied also to all 

 jointed organs in its vicinity, and 

 used for a similar purpose, which 

 indeed are the precursors of feelers 

 and antenna?. It is to these organs 

 that polypes are indebted for what 

 constitutes their principal orna- 

 ment, that resemblance of a plant 

 or shrub in full blossom, adorned 

 with crimson or orange-coloured 

 flowers. In the fixed polypes, the 

 tentacles are the only motive organs. 

 The tentacles of the fresh-water 

 polypes, forming the locomotive 

 genus hydra, are not, as those of 

 the fixed marine ones, shaped like 

 the petals of a blossom, but are 

 long hair-like flexible arms, some- 

 what resembling the branches of a 

 chandelier. Amongst the Radiaries, 

 tentacles exist in some genera, and 

 not in others. In the Stelleridans 

 and Echinidans, there are no ten- 

 tacles, but the Fistulidans present 

 a floriform coronet of tentacles. 

 Tentacles as exploratory, prehen- 

 sory, and locomotive organs, exist 

 in several other classes of animals. 

 In none, however, are they more 

 remarkable than in the Cephalo- 

 poda: in tbese animals they are 

 used as arms for prehension, as 

 legs for locomotion, as sails for 

 wafting their possessors over the 

 boundless deep, as oars for passing 

 through its waves, as a rudder for 

 directing their course, and as an an- 

 chor for fixing themselves. Kirby. 



TE'RBIUM. A metal having an earthy 

 oxide. Symbols Tb. 



TEKEBE'LLA. A genus of Annelidans, 

 or annulose animals, placed by 

 Cuvier in the order Tubicola. They 

 are inhabitants of the sea, and are 

 met with generally in shallow 

 water, on the coasts* and on shells, 

 &c. The body is oblong, creeping, 

 naked, often enclosed in a tube, 

 furnished with lateral fascicles, or 

 tufts, and small branchias ; mouth 



placed before, furnished with lips 

 without teeth, and protruding a 

 clavate proboscis; feelers numerous, 

 ciliate, capillary, seated round the 

 mouth. Terebellae not being pro- 

 vided by nature with any external 

 shell, endeavour to furnish them- 

 selves with an armature. For this 

 purpose they collect grains of sand, 

 or fragments of decayed shells, or 

 other substances, which they agglu- 

 tinate together by means of a viscid 

 exudation, so as to form a firm 

 defensive covering, like a coat of 

 mail. 



TE'REBRA. A genus of turreted subu- 

 lated marine univalves : the open- 

 ing short, and notched in the lower 

 part. The basis of the columella 

 twisted : found fossil in the envi- 

 rons of Paris. 



TE'REBRATESTG. A term applied to 

 shells which form holes in rocks, 

 wood, &c., and reside therein. 



TEREBRA'TTTLA. A genus of the class 

 Brachiopoda. TerebratulaB are ma- 

 rine'Jbivalves found moored to rocks, 

 shells, &c., at depths varying from 

 ten to ninety fathoms. The valves 

 are unequal and united with a 

 a hinge, but having no ligament : 

 the summit of one, more salient 

 than the other, is perforated to 

 permit the passage of a fleshy 

 pedicle, by means of which the 

 animal attaches itself to rocks, 

 shells, &c. The recent species are 

 few, but the fossil are very numer- 

 ous, lu the fossil shell, the oper- 

 culum which serves for the attach- 

 ment of the animal to the object to 

 which it is moored, can rarely be 

 traced. The casts of some species 

 of fossil Terebratulae are of a most 

 extraordinary form. These casts 

 are said to have been first noticed 

 by Pliny, who describes certain 

 stones, some of which were white 

 and others brown. Agricola next 

 noticed these bodies, as having been 

 found whilst digging near the fort- 

 ress of Ehrenbreitstein, in Treves. 



