Isosoma.–So much has been lately written about this genus that it may be dismissed with a few words. The Eurytomidae, to which it belongs, were considered by Nees to be in a debatable state between the chalcidiae and the cynips tribe, and though they are now fixed with the chalcidiae, there is still matter for argument as to their maintenance by animal life, or by vegetable life, or as to how they are divided between these two means of existence.