The species of Leiognathus described below apparently has a very wide distribution in Africa and is also found in Mauritius, China, India and South America. It seems indeed to be the common blood-sucking Gamasid mite of poultry in these countries. As it is highly probable that this parasite transmits spirochaetosis, and perhaps other diseases of the fowl, it is desirable that further information about its distribution and life-history should be obtained. Two instances of this mite attacking man are recorded below in the list of localities.