240 Benj. D. Walsh on the Insects fnhaliting tJic Galls 



tennse a double law seems to prevail here ; for on the one hand there 

 are several Ichneumon and Gryptus, where the flagellum % is black im- 

 maculate and the flagellum 9 is broadly urn-annulate with white or 

 yellow; and on the other hand it is very generally the case, that the 

 % scape is white or yellow beneath, and the 9 scape black immacu- 

 late.* 



In one apparently trivial sexual character that is not colorational 

 but structural, the two families, Tenthredinidse and Ichneumon idee, 

 agree universally, so far as I have observed, thus indicating their com- 

 mon origin from a very remote source ; and as I do not know that it 

 has been hitherto published, it may as well be stated here. Not only 

 are the % antenna very generally longer than those of 9 — which is 

 common almost every where in Insects — but they arc universally much 

 more compressed or vertically dilated in proportion to their length. So 

 that antennal joint 3, for example, though of the same proportional 

 length with regard to the other antennal joints in both sexes, and 

 therefore absolutely longer in a $ than in a 9 of the same size belong- 

 ing to the same species, will be perhaps only twice as long as wide in % , 

 while in 9 , from the compression or dilatation being proportionally so 

 much less, it will be three or four times as long as wide. — I leave the 

 believers in the Creative Theory to account for all these facts as they 

 best can, or, if they prefer it, to repose calmly and blandly in the bo- 

 som of the Shandean Philosophy, viz : that it has pleased God to make 

 everything thus and so, and that is enough for us. 



* There are so many of our N. A. Ichneumonidce undescribed, or described in 

 one sex only, or % 9 described as distinct species, or described without stating 

 the sex, that I can only give the few following examples of the above rules; 

 but I am sure, from the many hundred species examined by me, most of them 

 undescribed, that these rules are very generally as stated. Pimpla pedalis Cres- 

 son, (% only described); Pimpla [Cryptus] conquisitor Say {—plurivinctus Say); 

 Pimpla [Ichneumon] inquisitor/ Say,( 9 only described); Ccralosoma apicalis Cres- 

 son ; Cer.fasciata Cresson; Labena [Cryptus] grallator Say and Cresson, (=ilfe.so- 

 chorus fuscipennis Brulle); Ichneumon morulas Say, ( % undescribed by Say, and 

 = Trogus flavitarsis Cresson); Ichn. otiosus Say, ( 9 only described); Ichn. comes 

 Cresson, (% only described); Ichn. grandis Brulle, ( % =ambiguus Cresson, 9 = 

 regnatrix Cresson); Ichn. rufiventris Brulle ; Cryptus crassicornis % Cresson, ( 9 

 =robustus Cresson): Cryptus sponsor (England); and Mcsostenut, thoracicus Cres- 

 son. The above all from my own collection. Also from descriptions, where one 

 or both sexes are wanting in my collection, Ichneumon compt us Say; Ichn. na- 

 nus Say ; Ichn. montanus Cresson ; Cryptus extrematis ( — mus?) Cresson; Hctni- 

 ieles incerfus Cresson, (Cuba); Mesostenus semialbus Cresson, (Cuba); E.retustes 

 scutellaris Cresson: Anomahn? recurvus Say; Peltastes pollinctorius Say ; and 

 Arotes [Accenitus] decorus Say. 



