Published online by Cambridge University Press: 31 May 2012
The present paper brings together the latest knowledge on the species of Mecormmu known to occur in the Nearctic region. Study of the genitalia, external structures, and distribution, show that species vary considerably in structure and colour, and these variations have contributed in the past to the confusion in naming the species of Mecomma. Lack of specimens in collections has also hindered the study of this group and it is only within the last few years that large collections made in Canada and the United States have helped to solve somc of the problems.