: The amino acid sequences of osteocalcins from cortical long bones of goat, pig and wallaby have been determined by manual microsequencing methods. The location of the gamma-carboxyglutamic acid residues were identified by N-terminal degradation of peptides in which these residues had been tritium-labelled in the gamma-H position and subsequently thermally decarboxylated to glutamic acid residues. Glutamic-17 is not gamma-carboxylated in wallaby osteocalcin, unlike other osteocalcins so far sequenced (except human). This may be related to sequence changes in the flanking residues. Proline-9 is fully hydroxylated in wallaby osteocalcin, despite the sequence substitution Ala-8----Phe-8.