THORAX OF WINGED INSECTS. 461 



Scutellera by Lamarck. In some other species of this genus, or 

 sub-family, the scutellum is transverse, which gives the insects 

 a very singular appearance. {Canopus piuictatus, Leach, figured 

 in Griffith's Trans. Regn. An. pi. 92.) In the Ploteres of 

 Latreille we find, on the contrary, the prothoracic shield 

 produced over and entirely concealing the scutellum of the 

 mesothorax. The same occurs, but rarely, amongst the Geo- 

 coriscv, as in the Rediivms sp'midorsis and dorsalis, Gr. R. 

 Gray, (Griff. Trans. Regn. An. pi. 9L) 



In the two preceding orders we find the scutellum at its 

 highest state of development. Indeed its existence has been 

 altogether denied in other orders by some authors.* Now the 

 two former orders, in which its greatest development takes 

 place, are those in which the upper wings serve merely as 

 organs of defence to the lower pair, not being employed in 

 flying ; hence we may be warranted in regarding the meso- 

 thoracic scutellum as necessary for the support of the upper 

 wings, keeping them in their place both when at rest and ex- 

 panded; and hence it is, when these upper wings become active 

 instruments of flight, the scutellum becomes less conspicuous ; 

 but it is equally true that it still exists in all the other orders. 



In the saltatorial Orthoptera the upper surface of the meso- 

 thorax is also entirely, or nearly, concealed by the prothorax; 

 but on removing the latter a small elevated scutellum will be 

 perceived at the base of the posterior margin of the front 

 wings. 



In some of these {Tetrix, Latr.) the prothorax is posteriorly 

 produced into a long appendage concealing the remainder of 

 the thorax as well as the abdomen, which appendage has been 

 mistaken by Fabricius and Curtis for the real mesothoracic 

 scutellum. Serville has described a singular genus of Ortho- 

 ptera from New Zealand, having the elytra membranous, and 

 entirely concealed by the metathorax, which he describes as 

 being very long, pointed behind with a central line, giving this 

 part the appearance of two elytra soldered together ; he de- 

 scribes the prothorax as separated from the mesothorax, and 

 the latter from the metathorax, by a transverse line. From the 

 figure of this insect, however, (published in the plates of the 



=> " Glossata nullo gaudent scutello." — Fair. Olivier also was of the same 

 opinion, considering also the Orthoptera and Homoptera to be similarly circum- 

 stanced. 



