INTRODUCTION 



What .1 wide field, therefore, remaius to be iuveatigated before avo shall become 

 acquainted with the 600,000 or even 400,000 species supposed by Messrs Kirl)y and 

 Spence to exist; and how absurd does it seenv to consider our systems or rather sys- 

 tem as firmly established whilst so little is comparatively known.— Wkstwood, in 

 1833. 



Although tho classification of insects is in a move satisf;ictory condi- 

 tion than when Prof. Westwood wrote these memorable words, more 

 than half a century ago, a tact due in great part to this Nestor of 

 entomology and his contemporaries, our system of classification can 

 not yet be considered firmly established. Instead of 000,000 species 

 to deal with, later estimates place them at millions. Messrs. Sharp 

 and Walsingham in 1889 placed them at two millions; while the latest 

 authority, that of Dr. G. V. Riley, 1892, indicates that there are perhaps 

 10,000,000 species existing on the globe. 



In these pages it is my province to treat of only a small proportion of 

 this intricate and perplexing aggregate of forms, as found in America, 

 north of Mexico, viz: those of the single fanuly Proctotrypid*. 



The Proctotrypidiii, by some authorities, are considered to be closely 

 allied to the Chalcididic and, in a systematic arrangement of the 

 hymenopterous families, usually follow them in our manuals and cata- 

 logues. 



I consider, however, that they have but little aflinity with the Chalci- 

 didiT) and that this arrangement is unnatural. They are in every re- 

 spect more closely allied to the Ilymenoptera aculeata, the Chrysidida3, 

 Scoliida^ Mutillidic, and Thynnidiii; while in the Terebrantia, I be- 

 lieve, they approach closest to the parasitic Cynipidai {Allotria, Encoila, 

 and FujHes). 



In a natural arrangement, therefore, they should be placed at the 

 head of the Terebrantia; for after the removal of the group Mymarina^ 

 [which 1 hold with llaliday forms a separate and distinct family allied 

 to the Chalcidid*,] there is no relationship with the Ohalcidida^,. 



With the Mymarinse removed, there will be no difficulty in distin- 

 guishing, at a glance, a Proctotrypid from a Chalcid. In all true Proc- 

 totrypids the pronotum extends back to the teguhx' and the ovipositor 

 issues from the tip of the abdomen, the sheaths, except in a few ab- 

 normal cases, being conjoined and forming a more or less cylindrical 

 tube or scabbard for the reception of the two spicuhii and the ovipositor 

 proper; whereas, in all Chalcids the pronotum never extends back to 



