 In 1919 , Clark worked as the assistant to the entomologist on probation in the Western Australian Department of Agriculture , but in 1920 , he took on this position full @-@ time . He started to publish his first articles about pest insects and ants from 1921 ; in 1926 he became an entomologist at the National Museum in Melbourne , remaining there for 20 years . Clark continued to publish more articles until he resigned from the National Museum of Victoria in 1944 . Living in poverty , Clark lived a reclusive life , publishing his last book in 1951 . He died on 1 June 1956 at the age of 71 , survived by his six children . One of Clark 's most notable achievements was describing Nothomyrmecia macrops , the most primitive living ant . Several ants have been named after him in recognition of his contributions . 
