6S0 EXTERNAL ANATOMY OF INSECTS. 



frequently nearly circular, and differing occasionally, as 

 has been before observed 3 , in the different areas: it some- 

 times occurs that there are no traversing nervures b , when 

 the wins of course is without areolets. In the Hetero- 

 pterous Hemiptera the type of neuration, as to the wing, 

 seems borrowed from the Coleoptera, a further proof that 

 these are the analogues of that Order amongst the Hau- 

 stellata Clairv. In these the nervures usually are few 

 and dispersed, and seldom form any closed areolets. If 

 you examine any Scutellera, Pentatoma, or Lyga?us, you 

 may trace the uncinated, forked, serpentine, and insu- 

 lated nervures of Coleopterous insects; in Gerris and 

 Velia there is an approach to the neuration of some 

 Homopterous species, and in Belostoma &c. the wing is 

 reticulated by spurious nervures. In the Homopterous 

 section there are several types of neuration ; thus the Ful~ 

 gorcc resemble the OrtJioptera in this respect; while the 

 Tettigoniae F., &c, approach nearer to the Hymenqptera 

 and Diptera, and have their apical areolets circumscribed 

 'within the margin by a traversing nervure ; in Flata, 

 &c, the areolets are mostly formed, not by traversing 

 nervures, but by the branching of the longitudinal ones; 

 in this respect they are not unlike the Lepidoptera. In 

 this last-named Order there are some variations with re- 

 gard to their neuration — thus, amongst the butterflies in 

 Urania^ &c, there is no closed areolet in any of the 

 wings, and almost all thenervures diverge from the base c ; 

 in Morpho, &c, there is only one in the primary wing d ; 

 in Heliconia, &c, there is one in both wings ; amongst 



1 See above, p. 624. b Stoll figures Empusa as without 



them, t. ix./. 35. but? I have a nondesc. Phasma ? without them. 

 Jones in Linn. Trans, ii. t. viii./. 2. ,} Ibid. f. 5. 



