Am-blyp´o-da [Gr. amblys, blunt; pous, foot.] An extinct order of ungulates having elephantine feet and whose navicular bone was supported by the cuboid.
Am-blys´to-ma [Gr. amblys, blunt; stoma, mouth.] A genus of amphibians remarkable for the transformations they undergo. When undeveloped they represent the formerly recognized genus Siredon. Some species are called axolotls.
Am´i-a [Gr. amia, a kind of tunny.]
Am-i-to´sis [Gr. a-priv.; mitos, thread.] Direct cell-division; cell-division without the formation of nuclear figures.
Am´mon-ites [Egyptian Amon.] Fossil cephalopod shells.
Am´nion [Gr. amnion, fœtal membrane.] A membranous sack containing fluid which envelopes the embryo in the classes of reptiles, birds and mammals.
A-mœ´ba pro´te-us [Gr. amoibe, change; Proteus.] A unicellular animal; a Protozoan.
Am-phib´i-a [Gr. amphi, double; bios, life.] A class of vertebrates whose young are fish-like and have gills: the skull has two condyles and a parasphenoid.
Am-phi-mix´is [Gr. amphi, double; mixis, mingling.]
Am-phi-ox´us [Gr. amphi, double; oxys, sharp.] A small worm-like vertebrate whose body tapers at both ends. The skeleton is notochordal; skull, brain, auditory, and renal organs are absent.