376 GLOSSAr.v. 



Sertularida (Lat. sertum, a wreath). An order of tlie ITydrozoa. 



Sessile (Lat. sedo, T sit). Not supported upon a stalk, but attached by a base. 



Siliceous (Lat. sdex, tlint). Composed of flint. 



Siphon (Gr. a tube). Applied to the respiratory tubes of many of the MoU 



Jusca; also tq other tubes of diflierent functions. 

 SiFHONOPHOR.v (Gr. siphon, a tube ; pkero, I carry). A sub-class of the 



Ilydrozoa. 

 SiRENiA (Gr. seirPii, a mermaid). An order of Mammalia comprising the 



Dugongs and Manatees. 

 SOLIDUNGULA (Lat. solidus, solid; ungula, a hoof). The group of Hoofed 



Mammals comprising the Horse, Ass, and Zebra. 

 Somatic (Gr. sovia, body ). Connected with the body. 

 Somite (Gr. soma). A single segment in the body of an Articulate animal. 

 Spicula (Lat. spiodfrn, a point). Pointed needle-shaped bodies. 

 Spinnerets. The organs by means of which Spiders and Caterpillars spin 



threads. 

 Spongida (Gr. spoggos, a sponge). The division of the Protozoa commonly 



known as Sponges. 

 Sternum (Gr. sternmi). The breast-bone. 



Stomapoda (Gr. stoma, mouth ; podes, feei). An order of Crustacea. 

 Stomatode (Gr. stoma, mouth). Possessing a mouth.. The Infusoria are 



thus often called the Stomatode Protozoa. 

 Strepsiptera (Gr. strepho, I twist ; pteron, a wing). An order of Insects in 



which the anterior wings are represented by twisted rudiments. 

 Strepsirhina (Gr. strepho, I twist ; rhines, nostrils). A group of the Quad. 



rumana. 

 Suctorial. Adapted for suction or for iniV)il)iiig fluids. 

 Supba-(E80PHageal. Placed above the gullet or oesophagus. 



TabuLjE (Lat. tahxila, a tablet). Horizontal plates or floors which are found 



in many Corals. 

 Tactile (Lat. ta.ngo, I touch). Connected with the sense of touch. 

 T-eniada (Gr. tainia, a ribbon). The order of Scolecida comprising the Tape- 

 worms. 

 Tarso-metatarsus. The single boue produced in Birds by the imion and 



anchylosis of the lower part of the tarsus with the metatarsus. 

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



ankle (or "instep" of man), corresponding with the wrist (carpus) of the 



anterior limb. 

 Telkostei (Gr. ieleios, perfect ; osteon, hone). An order of Fishes often 



spoken of as the Bony Fishes. 

 Telson (Gr. a limit). The last joint in the abdomen of the Crustacea. 

 Tenuirostres (Lat. tenuis, slender; rostrum, beak). A group of the Perching 



Birds characterised by their slender beaks. 

 Terrestrial (Lat. terra, earth). Living upon dry land. 

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



sometimes called Testacea. Also, the calcareous shell of Sea-urcliins. Also, 



the thick leathery outer tunic of the Sea-squirts, Tunicata. 

 Tetrabranchiata (Gr. tetra, four; bragchia, gills). Tlie order of Ceplmlo- 



poda characterised by the possession of four gills. 

 Thalassicollida (Gr. thodassa, sea ; kolla, glue). A division of Protozoa. 

 Theriodontia {Gr, therj beast ; odo%is, tooth). An order of extinct Reptiles 



with teetli of a Mammalian type. 

 Theriomorpha (Gr. ther, beast ; morphe, shape). Employed by Owen to 



designate the "tail-less Amphibians," such as Frogs and Toads. 

 Thorax (Gr. thorax, tlie breast, or a breast-plate). In the higher animals, 



the thorax is that region of the body which is placed between the abdomen 



and the head. 

 Thysanura (Gr. thusanoi, fringes ; oura, tail). An order of Insects. 

 Tibia. The shin-bone, corresponding to the radius of the fore-limb, and 



being the innermost of the two bones of the leg. 



