Parliament of Australia
From 1901 to 1949, the House consisted of either 74 or 75 members (the Senate had 36). Between 1949 and 1984, it had between 121 and 127 members (the Senate had 60 until 1975, when it increased to 64). In 1977, the High Court ordered that the size of the House be reduced from 127 to 124 members to comply with the nexus provision. In 1984, both the Senate and the House were enlarged; since then the House has had between 148 and 150 members (the Senate has 76).
Australian House of Representatives
The House of Representatives currently consists of 150 members, elected by and representing single member districts known as electoral divisions (commonly referred to as "electorates" or "seats"). The number of members is not fixed but can vary with boundary changes resulting from electoral redistributions, which are required on a regular basis. The most recent overall increase in the size of the House, which came into effect at the 1984 election, increased the number of members from 125 to 148. It reduced to 147 at the 1993 election, returned to 148 at the 1996 election, has been 150 since the 2001 election, and will increase to 151 at the 2019 Australian federal election.