56 Psyche [June 



approximated, there is usually a sternal fulcrum of the coxa 

 (Crampton and Hasey, 1. c), and other characters showing that 

 they have much in common. 



I would group the Psocidse, Thysanoptera, Mallophaga, Ano- 

 plura (Pediculidse), Hemiptera and Homoptera in another su- 

 perorder, the Pcmhomojdera, but by so doing, I would not minimize 

 the close relationship of the Psocids to the Neuroptera, and the 

 close approach of the Hemipteroid lines of development to those 

 of the Mecoptera and Diptera. The Hymenoptera are closely 

 allied to both the Psocidse and the Neuroptera, and I have been 

 unable as yet to determine in which of the two superorders they 

 should be placed. 



In connection with the discussion of the interrelationships of 

 the orders of insects, it may be of some interest to note that it 

 would appear that in the interesting little Crustacean Bathynella 

 we have a form very like the common ancestors of the Insecta 

 and "Myriopoda" {sensu lato). Bathynella belongs to a very 

 ancient group of Crustacea, and the number of segments com- 

 posing its body, the character of its appendages (which are lack- 

 ing on the last segments), etc., are all in accord with the view that 

 it is very like the ancestors of the Proturan insects. Bathynella 

 is also very like the probable ancestors of the Symphyla-Pauro- 

 poda, a group which has departed but little from the condition 

 characteristic of the ancestors of the "JNIyropoda" as a whole. 



Bibliography. 



The following articles treat only of the Neuroptera and Mecop- 

 tera. Bibliographies of works on Trichoptera, Diptera, etc., will 

 be given in articles dealing with the genitalia of these groups. 

 1914. Champion. Revision of the Mexican and C. Amer. 

 Chauliognathidae, Based on the Genital Armature of the 

 Males. Trans. Ent. Soc, London, 1914, p. 128-. 

 1918. Crampton. Phylogenetic Study of Genitalia of Males of 

 Lower Insects. Bull. Boooklyn Ent. Soc. 

 EsBEN Peterson. Monograph of the Mecoptera. Coll. 

 Zcol., Baron Selys-Longchamps. 

 1895. Felt. Scorpion-flies. 10th Rpt. N. Y. State Entomolo- 

 gist, p. 463-. 



