1 44 GLOSSARY. 



Te'res ml'nor (L. feres, rounded ; minor, smaller). A muscle 



passing from the scapula to the humerus. 

 Ter'gal facet' (L. tergum, the back). The dorsal, smooth, 



anterior surface of each somite in the Crustacea, on which 



the posterior part of each previous somite moves in flexion 



and extension of the abdomen. 

 Ter'gum (L. the back). The dorsal part of the carapace in the 



Crustacea. 



Test ") (L. testa, a shell). A term applied to the calcareous 

 Tes'ta ) covering of sea urchins, &c. The outer coat of the 



seed of a plant. 



Tes'tis (L. atesticle). Thegland which secretes the spermatozoa. 

 Testudi'nea (L. testudo, testudinis, a tortoise). A group of the 



Chelonia which comprises the land tortoises. 

 Tetrabranchia'ta (Gr. tetras, four ; branchia, a gill). A group 



of the Cephalopoda having four gills. 

 Tetradac'tyle (Gr. tetras, four; daktulos, a finger or toe). 



Having four digits. 

 Tetra'merous (Gr. tetras, four; meros, a part). Consisting of 



four portions. 

 Thalamence'phalon (Gr. thalamos, a bed, couch ; enkephalon, 



the brain). The "inter-brain," comprising the thalami 



optici, pineal gland, pituitary body, and third ventricle. 

 Tha'lamus op'ticus (L. optic couch). The name of each of two 

 * structures in the side-walls of the third ventricle of the 



brain, from which the fibres of the optic tract partly arise. 

 Thalas'sa-col'lida (Gr. thalassa, the sea; holla, glue). A group 



of Protozoa. 

 Thau'motrope (Gr. thauma, a wonder; trepo, I turn). An 



instrument in which figures in series of different positions 

 .are painted near the circumference of a disc, and the 



reflections of these, being looked at in a mirror through 



openings in a card revolving with them, are seen in the 



form of figures, each of which appears to perform the whole 

 movement represented in stages on the disc. 

 The'ca (Gr. a sheath, envelope). Applied to the synovial 



sheath of a tendon. Also the name given to the calcareous 



cup in some of the Actinozoa. 

 The'codont (Gr. theke, a sheath; odous, odontos, a tooth). 



Having the teeth lodged in alveoli ; applied to the extinct 



Protorosauria, a group of the Lacertilia. 



