( n. pl. )
That group of vertebrates which develops in its embryonic life the envelope called the amnion. It comprises the reptiles, the birds, and the mammals.
( n. pl. )
That group of vertebrates which develops in its embryonic life the envelope called the amnion. It comprises the reptiles, the birds, and the mammals.
Webster's Revised Unabridged English Dictionary. Пересмотренный полный словарь английского языка Webster. 2012