BY R. J. TILLYARD. 



229 



with the free edge of the upper slide, no tlmt the whole ni tlio 

 two wings lay flatly out over this slide (Text-fig. 3). No cover- 

 slip was used. (This same operation was afterwards performed 

 on other pupa?, with the addition of a cover-slip let down gently 

 upon tlie wings; but tliis was found to cause displacement of 

 some of the trachea?). The wings were then photographed by 

 njeansc^ Keichert's photo-micrographic apparatus, and the results 



obtained which are shown 

 in Plate xi., figs. 1-2. Tm- 

 Miediately afterwai'ds, the camera- 

 lucida drawing of the traclieation, 

 shown in Text-fig.5, was obtained 

 from this same pupa. Thus at last 

 success was obtained. T may add 

 that photographs and th*a wings 

 were made from several other pujja' 

 of C. Hiynata, and that all of theses 

 agi^eed practically in ever}- single 

 detailf ^^'ith tlie one figured. Thus 

 the results do not rest upon a single 

 observation, but ai-e hasefl up(ni a 



Toxt-fig.3." 

 considerable mass of evidence 



Critical Htndij of the Wiiuf-Ycnation of Chrysopa signata Walker. 



We can now pass to the study of the traclieation of the pupal 

 wing, with a view to elucidating the venation of the imaginal 

 wing. This latter is shown in Textfig.4 (p.230), with the usually 

 accepted nomenclatui'e of the veins, according to the Comstock- 

 Needham notation. This nomenclatiu-e has been employed b}- 

 Banks, Petersen, Navas, and other systematists for the past ten 

 years or moi-e. As far as I can gather, nobody has yet doubted 



* Diagram to show method of studying the pvipal wings of Chrysopa; 

 ( x8) : «. coil of left antenna; a , cut end of right antenna; Fir, forewing; 

 Hw, hindwing: L, lower glass slide; m, pupal mandibles; l\ upper glass 

 slide. 



tin some specimens, there may be a small fork at tlie extreme tip uf Rs 

 or Sj. 



