前缘脉
- 网络costa;costal vein
前缘脉-
亚前缘脉弓的作用相信是加强了因翅基骨板发达而相互远离的纵脉间的连结作用。
The hypothesized function of subcostal brace in mayflies is to strengthen the connection between distantly separated longitudinal veins because of sclerite plate at radius vein base .
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翅不具有横脉，前缘三条纵脉明显发达。
Wing has no horizontal arteries veins , three costa veins developed significantly .