#Tho' rax#, the region of the body between the head and abdomen. #Tib' i a#, (1) the shin-bone; (2) the fourth joint of an insect's leg. #Tooth#, (1) an organ used in mastication; (2) a tooth-like projection. #Tra' che a#, a tube which carries air either to the respiratory organ or to the tissues. #Trunk#, the portion of the body between head and tail. #Tu' ber cle#, a knob-like projection. #Ul' na#, that bone of the forearm which is on the same side as the little finger. #Um' bo# (pl. #umbones#), an elevation near the anterior end of a bivalve shell. #Un' gu lates#, hoofed mammals. #U re' ter#, a duct connecting the kidney with the urinary bladder. #U' ro style#, a long bone forming the hinder extremity of the vertebral column of tailless amphibia. #Vac' u oles#, small, clear spots in cells, filled with a watery fluid. _See_ Food-vacuoles _and_ Contracting vacuoles. #Valve#, (1) a membranous fold which allows the blood, or other fluids, to flow in only one direction; (2) one of the two parts of the shell of a bivalve. #Vein#, (1) a blood-vessel carrying blood toward the heart; (2) one of the tubular thickenings of an insect's wing. #Ve' na ca' va#, a large vein emptying into the right auricle of the heart. #Ven' tral#, situated on the under surface. #Ven' tri cle#, any cavity of a hollow organ, as of the brain or heart. #Ver' mes#, the worms, a poorly defined group of animals, showing bilateral symmetry but without segmented appendages. #Ver' te bra#, one of the bones of the spinal column. #Ver' te brates#, animals having a backbone. #Vi bris' sæ#, long hairs on the face. #Vis' ce ra# (pl. of #viscus#), the organs of one of the great cavities of the body (the abdomen, the thorax, or the cranium), usually meaning those of the abdomen. #Vi va' ri um#, a cage in which living animals are kept. #Warning colors#, bright colors which render an animal free from attack. #Whorl#, a single coil in the spire of a gasteropod shell. #Yolk#, food material of an egg. End of the Project Gutenberg EBook of A Guide for the Study of Animals, by Worrallo Whitney and Frederic Lucas and Harold Shinn and Mabel Smallwood