The lowest selection of Vertebrata, including the amphioxus, which no skull is present.
[NL., fem. sing.] In teratology, a malformation consisting in a whole absence of the bones and integuments developing the vault for the skull. In addition written acrany.
[capitalized] [NL., neut. pl.] A name recommended by Haeckel as a class designation for Amphioxus or Branchiostoma; a synonym of Myelozoa or Leptocardia (which see). Also known as Acephala. See Amphioxus and Branchiostoma.
A theory or system of social reform which contemplates a complete reconstruction of society with a more just and equitable distribution of property and labor In popular usage the term is often employed to indicate any lawless revolutionary social scheme See Communism Fourierism Saint Simonianism forms of socialism...