0! EXTRA-EUROPEAN Till C1IOPTERA . 



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formed after the same plan. In both, the antenna) of the female are 

 much shorter than those of the male, in hurneralis remarkably so. 

 In Jinitimus these organs are slender throughout in the <S , whereas 

 in hurneralis they are gradually incrassate in the apical portion. 



A completely analogous formation of the eyes in both male and 

 female is to be found in the niicro-lepidopterous genus Adela. 



I have diagnosed and described this extraordinary genus anew, 

 because the description given by Mr. Walker is insufficient. It 

 appears to me that, having regard to the homologies of the 

 arrangement of the nervures in Trichoptera, an error has been 

 frequently committed, of which I have myself been guilty in 

 some previous descriptions in former papers. I allude especially 

 to the area or cell which has been called the " cellula thyridii " 

 in the anterior wing. To Kolenati we are indebted for a very 

 lucid explanation of the different veins, areas, and cellules ; and in 

 his index wing (Gen. et sp. Trichop. pt. 1, tab., i. f. 1), taken from 

 Glyphotcelius, the " cellula thyridii " is the area between the two 

 veins which he terms " radii ramus thyrifer," and " radii ramus 

 clavalis," and which I have called (Trichop. Britannica) the " su- 

 perior and inferior branches of the ramus thyrifer." But in almost 

 all genera of Hy dropsy chidae, and in several genera of Lepto- 

 ceridse, e. g. Ascalaphomerus, Anisocentropus, Ganonema, Asoto- 

 cerus, Calamoceras, Seteroplectron, &c, the superior branch of the 

 ramus thyrifer (" radii ramus thyrifer " of Kolenati) furcates near 

 the middle of the wing ; and this furcation is generally closed by a 

 transverse veinlet placed nearly on a level with that closing the 

 discoidal cell, and forming a cellule, which has been usually termed 

 the " cellula thyridii," though the true cellula that should be so 

 called, equivalent to that in the Limnophilida?, &c, lies beneath it, 

 extending to near the base, and usually ending soon after the 

 commencement of the cellule formed by the connected ramules of 

 the superior branch. This latter cellule, then, I propose to call 

 the " cellula inediana" A reference to the outline figures of the 

 wings of any of the above-named genera will more fully explain 

 my meaning. 



In Mr. Walker's description of the genus Ascalaphomerus the 

 words " cell of the thyridium " should then read " median cel- 

 lule ; " and his " inter claval areolet " is in reality the true " cel- 

 lula thyridii." 



Heteroplectron, gen. nov. 

 Calcaria 2, 4, 2, ; 2, 4, 4, $ . Maris tibia? posticse fimbriis 



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