EXTERNAL ANATOMY OF INSECTS. 609 



men is horizontal, and covers the back of the animal, and 

 the Intermediate and Costal are vertical and cover its 

 sides ; the former, however, in some cases, only forms the 

 angle between them. Sometimes in these the right-hand 

 one is laid upon the left, as in Acheta; and sometimes the 

 reverse of this takes place, as in Acrida K. With regard 

 to the folding ofthetegmina. the most remarkable instance 

 that occurs is that of Acheta monstrosa, in which the ends 

 of both these organs and the wings, in repose, are folded 

 like a fan, and then rolled up like a serpent 3 . 



5. Shape. The shape of tegmina is various. In the 

 Blattcs and some Mantes they are more or less oblong; 

 in Mantis precaria, strumaria b i and others, they incline 

 to elliptical; in Phasnia Gigas and Acheta monstrosa they 

 are rather panduriform c ,• in M. gongyloides they are 

 semi-cordate d ; in Pterophylla trapeziformis they are 

 rhomboidal e ,- in Conocephalus erosus they are sinuated ; 

 in Locusta Leach they are usually linear or linear-ob- 

 long f ; in Pterophylla K. they generally terminate in a 

 short mucro g ; and in some of those Manlidce whose 

 tegmina simulate arid leaves, in a recurved one h . In 

 the Homopterous Hemiptera the shape of these organs 

 is less various. In the Fulgorellcc Latr. they incline to 

 a trapezium, sometimes to a pentagon ' ; in the Tet- 

 tigonice F. they approach to an obtuse-angled trian- 



* Stoll Grillons t. i. c.f.2. h Ibid. Spectres t. xxv.f. 9.5. 



and xi./. 42. ° Ibid. t. ii./. 5. Grillons t. i. c.f. 1. 



d Ibid. Spectres t. xvi.f. 58. e Ibid. Sauterelles a Sabr. t. iii. 



/. 7- By this name (Pterophylla) I distinguish those LocustcB F. 

 without a conical head that are veined like leaves. 



f Stoll Ibid. t. vi. a./. 18. and Pi,ate XXVIII. Fig. 19. 



E Stoll Sauterd. a Sabr. t. i— iii. h Ibid. Spectres t. iv.f. 14. 



■ Ibid. Cigalest. If. 1, 3—5. and t. vi./.31. 



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