GLOSSARY OF TECHNICAL TERMS. 365 
Ventral aorta. A large thick-walled elastic blood-vessel originating in the 
bulbous aorte. . 
Ventral plates. Gastrosteges. A row of shields along belly between throat 
and vent. 
Ventricle. One of the thick-walled chambers of the heart. 
Ventricles. Brain chambers. 
Versatile. Capable of being turned either way. 
Vertebra. One of the spinal column bones. 
Vertebral shields. Median series of shields on the carapace of turtles. 
Vertical. Up and down. 
Vertical plate. Frontal plate on top of head in lizards and snakes. 
Vesical vein. Vein from the urinary bladder to the abdominal vein. 
Vestibule. ‘Tht utriculus and sacculus when spoken of together. \ 
Villiform. Usually of slender crowded teeth in velvety bands. 
Viscous. Slimy. 
Vitreous humor. A gelatinous substance filling the posterior chamber of 
the eye. 
Viviparous. Bringing forth living young. 
Vocal vesicle. A loose fold of skin at angle of the mouth in some male 
frogs. This can be inflated at will to a spherical form during croak- 
ing. In the toads the throat simply swells out and retracts as the 
croaking is emitted. 
Vomer. Paired or single bone on roof of mouth in front. 
Web. Membrane connecting digits, 
W oliian body. ‘The mesonephros, or permanent kidney. 
Xiphiplastra. Last pair of large median bones forming plastron. 
Xiphisternum. Cartilaginous plate at tip of sternum. 
Zygapophyses. Points of bone affording more or less definite articulation to 
the vertebre. 
