INTRODUCTION Ixxvii 



cases intentionally by Koebele. The members of the tribe Mirini I look upon as 

 foreign, with perhaps one or two exceptions. 



The vast complex of forms included in the Pteromalidae can only be said to 

 be represented endemically by a minute Spalangia, a true forest insect, allies of which 

 may be expected to be found. 



The Eulophidae have a greater number of genera containing endemic species than 

 the Encyrtidae, but in most of these only one or two species have been described. 

 The Aphelininae and Tetrastichinae are foreign and need not be considered. The 

 Entedoninae, Elachistinae and Eulophinae must be considered as having endemic 

 species. These include seven genera and only eight species, as described. This, 

 however, gives an erroneous impression of the group, for a good many more species 

 have been collected (in several of these genera). After death most of them rapidly 

 dry, and distort to such an extent as to utterly unfit them for description. 



The vast group of Ichneumons are represented only by a single endemic species 

 of Echthromorpha and two of Glyptogastra (an endemic genus) in the Pimplinae ; 

 in the Ophioninae by three endemic genera Banchogastra, Pycnophion, and Pleiwo- 

 nciirophion (six species in all), as well as a large number of endemic species in 

 apodemic genera. Ophion has one species, Enicospilus 13, Eremotylus i, Atliyreodon 2, 

 Atrometus 11, Livineriwn (i), Lathrostizus^ -{■ Idecthis^ 2, Pristoniertis^ i. The claims 

 of the species in the four latter genera to be endemic are, however, more or less 

 doubtful, and one other species of Limnerium is certainly introduced. 



The Alysiidae and Braconidae are, doubtless, all foreign, excepting only the 

 minute Ecphylopsis nigra (the genus being endemic) of the sub-family Spathiinae. 



There are therefore 52 genera in the Hymenoptera represented by endemic 

 species (though in a few cases the endemicity of these is questionable) and these 

 species number 372, or seven species to a genus on the average. If we exclude those 

 questionable species, the average would be rather higher still. 



Comparing the Aculeate Hymenoptera, i.e. ants, bees and fossorial wasps, with 

 the remaining families or 'Parasitica,' we find in the former only 13 genera with 

 1 86 species, an average of about 14 species to the genus; in the latter 39 genera 

 also with 186 species, an average of 47 to the genus. 



This very great difference in the average of species in the two groups will no 

 doubt be subject to considerable alteration and will not prove so vast, as now appears, 

 though I believe it will remain considerable. In many cases, owing to their specialized 

 habits, the parasitic forms have less scope for a great increase of species owing to 

 their dependence on a limited number of hosts. Thus the Eulophidae, several of 

 which are parasitic on leaf-mining caterpillars, are limited in species by the comparative 

 scarcity of species of Lepidoptera having these habits. 



' Further observations render it certain that these have been introduced. 



