\ 



of the Order Thysanopttra. 221 



Older THYSANOPTERA. 



t. Eleven pairs of stiymata present ; hind pair of coxes most undely 

 separated; palpi shuile-jointed. (Species bearing a close general 

 resemblance to the Tubulifera ; rcelli and wings absent ; autennfe 

 7-jointed, joints broad and strongly characteristic ; spiracular 

 openings large and protected externally by specialized dorso- 

 lateral papilla; ; ninth abdominal segment elongated, longer than 

 the preceding j intermediate terminal hairs obsolete.) 



Suborder Polystigmata, mihi. 

 Containing the family Urothripidce, Bagnall. 



ll. Not more than four pairs of stigmata present ; intermediate pair of 

 coxce most widely separated ; palpi never less than 2-jointed. 



1. Female without an ovipositor ; last abdominal segment tubular in 



both sexes (ninth abdominal segment not exceptionally elongated, 

 and intermediate terminal hairs present ; antennre composed of 

 eight more or less strongly elongated and slender joints*, certain 

 of which bear one or more sense-conesj. Lower and upper 

 wings, when present, similar in structure, with only one median 

 longitudinal vein, which is only partially developed, sometimes 

 obsolete, and never reaches the tip of wing. 



Suborder Tubulifera, Haliday. 

 Containing the diagnosed families Phloeothrijndce, Haliday, and 

 IdolothripidcB, Bagnall. 



2. Female with a saw-like ovipositor ; last abdominal segment 



usually conical, that of male unlike the females and usually 

 bluntly rounded. Fore wing with at least one longitudinal 

 vein reaching from base to tip of wing. (The structure of the 

 wings, palpi, antennte, and ovipositor affords good characters for 

 tabulating the families.) Suborder Terebrantia, Haliday. 



Containing the diagnosed families Molothripidce, Haliday, and 

 Thripida, Haliday. 



When Uzel monograplied the Tliysanoptera in 1895 tlie 

 ultra- European species were unworked. Since then the 

 North-American forms liave received a good deal of attention, 

 whilst material from tropical and subtropical regions is 

 being received and dealt with. As a natural consequence, 

 highly specialized forms and groups of species that cannot 

 be regarded as members of the previously diagnosed families 

 have been discovered, though the tendency with workers in 

 the order has been to regard the three families Phloeo- 

 thripidse, 7Eolothripida3, and Thripidce as fixed and to fit 

 new and specialized genera into one or the other. To 

 eliminate difficulties as far as possible, I think it very 

 desirable to make certain divisions and subdivisions to 

 receive certain genera and groups, but shall be able to write 

 more on this matter when I have had the opportunity of 



* A few species possess 7-jointed antennae, undoubtedly derived by tho 

 fusion of the seventh and eighth joints. 



