INTRODUCTION. 



right to inclusion in our list. A considerable number 

 of others are met with casually, but can in no sense 

 be looked upon as British insects. As regards status, 

 then, our Orthoptera may thus be tabulated :- 



a. Thirty-one species considered to be indigenous. 



I). Eight aliens naturalised, however, as shown by their 



breeding here. 

 c. An uncertain but large and increasing number of casual 



visitors interesting, of course, but whose names must 



not appear on our lists. 



In order to show the position of the Order 

 Orthoptera within the Class Insecta, the scheme of 

 Insect Orders adopted is here given * : 



APTERYGOTA (wingless insects, supposed to have descended 

 from wingless ancestors): Order 1, Protnra; 2, Zor- 

 aptera; 3, Collembolat; 4,Campodeioidea; 5,Thysanura. 



ANAPTERYGOTA (wingless insects, whose ancestors were 

 probably winged) : Order 6, Mallophaga ; 7, Anoplura ; 

 8, Siphonaptera. 



EXOPTERYGOTA (winged insects, whose wings develop outside 

 the body, these Orders still containing- a fair number 

 of wingless, or imperfectly winged, forms). Order 9, 

 Orthoptera; 10, Plecoptera ; 11, Psocoptera ; 12, 

 Isoptera ; 13, Embioptera ; 14, Epherneroptera ; 15, 

 Paraneuroptera (= Odonata) ; 16, Thysanoptera; 17, 

 Hemiptera. 



ENDOPTERYGOTA (winged insects, whose wings arise as 

 invaginations of the hypodermis, and for a time 

 project within the body, containing but few wingless 

 forms). Order 18, Neuroptera; 19, Trichoptera ; 20, 

 Lepidoptera ; 21, Coleoptera ; 22, Strepsiptera; 23, 

 Diptera ; 24, Hymenoptera. 



AVe may define the ORTHOPTEEA (dofloc = straight ; 



foov = a wing) as: Insects with month formed for 

 biting, the maxillary and labial palpi bent// conspicuous 

 and the labium being divided in the middle; the fore- 

 wings (elytra, or tegmina) stiff but not horny, closed over 



* Compare "The Orders of Insects/' D. Sharp, 'Entomologist/ vol. xlii, 

 p. 270, 1909. 



f It is possible that one or two of the Apterygote groups should not be 

 classed with Insects proper. 



