6OO GLOSSARY. 



TABULA (Lat. tabula, a tablet). Horizontal plates or floors found in some 



Corals, extending across the cavity of the " theca," from side to side. 

 TACTILE (Lat. tango, I touch). Connected with the sense of touch. 

 T^ENIADA (Gr. tainia, a ribbon). The division of Scolecida comprising the 



Tapeworms. 



T.&NIOID (Gr. tainia; and eidos, form). Kibbon-shaped, like a tapeworm. 

 TARSO-METATARSUS. The single bone in the leg of Birds produced by the 



union and anchylosis of the lower or distal portion of the tarsus with the 



whole of the metatarsus. 

 TARSUS (Gr. tarsos, the flat of the foot). The small bones which form the 



ankle (or "instep" of man), and which correspond with the wrist (carpus) 



of the anterior limb. 

 TECTIBRANCHIATA (Lat. tectus, covered ; and Gr. Iragchia, gills). A division 



of Opisthobranchiate Gasteropoda in which the gills are protected by the 



mantle. 



TEGUMENTARY (Lat. tegumentum, a covering). Connected with the integu- 

 ment or skin. 

 TELEOSTEI (Gr. teleios, perfect; osteon, bone). The order of the "Bony" 



Fishes. 

 TELSON (Gr. telson, a limit). The last joint in the abdomen of Crustacea; 



variously regarded as a segment without appendages, or as an azygos 



appendage. 

 TENUIROSTRES (Lat. tennis, slender; rostrum, beak). A group of the 



Perching Birds characterised by their slender beaks. 

 TERGUM (Lat. for back). The dorsal arc of the somite of an Arthropod. 

 TERRICOLA (Lat. terra, earth ; and colo, I inhabit). Employed occasionally 



to designate the Earth-worms (Lumbricidte). 

 TEST (Lat. testa, shell). The shell of Mollusca, which are for this reason 



sometimes called "Testacea;" also, the calcareous case of Echinoderms; 



also, the thick leathery outer tunic in the Tunicata. 

 TESTACEOUS. Provided with a shell or hard covering. 



TESTIS (Lat. testis, the testicle). The organ in the male animal which pro- 

 duces the generative fluid or semen. 

 TETRABRANCHIATA (Gr. tetra, four ; bragchia, gill). The order of Cephalopoda, 



characterised by the possession of four gills. 



THALASSICOLLIDA (Gr. thalassa, sea; kolla, glue). A division of Protozoa. 

 THECA (Gr. theke, a sheath). A sheath or receptacle. 

 THECOSOMATA (Gr. theke; and soma, body). A division of Pteropodous 



Molluscs, in which the bodv is protected by an external shell. 

 THERIOMORPHA (Gr. iher, beast; morplie, shape). Applied by Owen to 



the order of the Tail-less Amphibians (Anoura.) 

 THORAX (Gr. a breastplate). The chest. 

 THREAD-CELLS. (See Cnidae.) 

 THYSANURA (Gr. tkusanoi, fringes ; and oura, tail). An order of Apterous 



Insects. 

 TIBIA (Lat. a flute). The shin-bone, being the innermost of the two bones of 



the leg, and corresponding with the radius in the anterior extremity. 

 TOTIPALMAT^J (Lat. totus, whole; palma, the palm of the hand). A group 



of Wading Birds in which the hallux is united to the other toes by mem- 

 brane, so that the feet are completely webbed. 

 TRACHEA (Gr. tracJieia, the rough wind -pipe). The tube which conveys air to 



the lungs in the air-breathing Vertebrates. 



TRACHEAE. The breathing-tubes of Insects and other Articulate animals. 

 TRACHEARIA. The division of Arachnida which breathe by means of tra- 

 cheae. 



TREMATODA (Gr. trema, a pore). An order of Scolecida. 

 TRICHOCYSTS (Gr. thrix, hair ; and kmtis, a cyst). Peculiar cells found in 



certain Infusoria, and very nearly identical with the "thread-cells" of 

 Coelenterata. 



TRILOBITA (Gr. treis, three ; lobos, a lobe). An extinct order of Cmstaceans. 

 TRITOZOOIDS (Gr. tritos, third ; zb'on, animal ; and eidos, form). The zob'id 



