Glossary of Technical Terms Relative to Amphibians 
and Reptiles. 
Abdomen. Belly. 
Abdominal cavity. Chamber of the celome containing the viscera. 
Abdominal shield. Posterior, or larger, of large shields on plastron joining 
bridge in most turtles. 
Abdominal vein. Vein extending from the pelvic veins to the liver. 
Abducent nerves. Sixth pair of cranial nerves, supplying the external rectus 
muscle of the eye. 
Abductor. A muscle that draws away from the middle of the body. 
Accessory nerves. Eleventh pair of cranial nerves, supplying muscles of the 
shoulder. 
Acetabulum. Surface for articulation of hind limb on pelvic-girdle. 
Acrodont. Teeth fixed by their bases to summit ridge of the jaw. 
Adductor. A muscle that draws towards the middle of the body. 
Adrenal bodies. A gland on the ventral surface of each kidney. 
Afferent. Conducing inward. Said of arteries, which convey aérated blood. 
Alisphenoid. A small bone on the front side wall of the brain-case. 
Alveola. Teeth-sockets. 
' Alvelolar surface. Part of turtle’s jaw, where alveola develop in other 
reptiles. 
Ampluarthrosis. A joint in which bony surfaces are united by intervening 
fibrous or fibrocartilaginous substance, so as to permit of slight move- ’ 
ment, as in the vertebre. 
Amphicelian. Double-concave, usually referring to vertebre. 
Ampulla. A dilation at the end of the semi-circular canal. 
Anal. With reference to the anus or vent. 
Anal plate. Plate just in front of vent in serpents, usually divided by a 
median suture. 
Anal shield. Posterior pair of shields or plates on plastron of turtles. 
Anchylosed. Firmly grown together. 
Angular. A small bone on back end of lower jaw. 
Angulo-splenial. Membrane bone along inner face of mandible. 
Annulus tympanicus. Ring of cartilage supporting tympanum. 
Anteorbital plate. Preorbital plate. Preocular plate. Developed as 1 or 
2 plates in front of eye in serpents, and its longest diameter usually 
vertical. 
Antrorse. ‘Turned forward. 
Anus. Vent. External opening of intestine. 
Aqueous humor. A watery fluid filling the anterior chamber of the eye. 
Arboreal. Dwelling in trees. 
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