76 Amials Entomological Society of America [Vol. VI^ 



in the membracid wing, there is a sharp bend at the point at 

 which the tracheae enter the body and it is difficult to secure a 

 mount in which the base and tip of the wing are in focus at 

 the same time. 



Various mounting media were tried, but for the wings of 

 this family glycerin jelly was uniformly the most satisfactory. 

 A drop of jelly was placed on the slide, the wing laid in the jelly, 

 another drop placed on the cover-slip and the latter placed at 

 once over the specimen. The mount was then quickly cooled 

 by placing a drop of ether on the cover-slip and fanning it to 

 insure rapid evaporation. Some of the mounts made in this 

 way have remained in good condition for over a year and bid 

 fair to last for a much longer period. 



Photomicrographs were then made of the specimen, using 

 whatever combination of objective and bellows were necessary 

 to bring out the desired details and to make the image fill a 

 5x7 plate. Since many of the nymphal wings are less than two 

 millimeters in length, the magnification is necessarily great, 

 but negatives can usually be secured sufficiently sharp to show 

 the points in question. Artificial light, secured by means of a 

 Nernst lamp and series of condensers, seemed to be more 

 desirable than sunlight for this work, mainly owing to the fact 

 that it was possible to secure a chart of uniform exposures for 

 the different magnifications. 



In cases where photomicrographs were not considered 

 necessary, careful camera lucida drawings were made, verified 

 by repeated comparisons. For the adult wings, the permanent 

 mounts (Canada balsam) of the wings themselves were used, 

 copied by projection drawings when figures were desired. 



Velox and solio prints from all negatives were made for per- 

 manent records in this study. The figures of nymphal wings 

 shown in this paper, however, are blueprints inked in with india 

 ink and afterwards bleached.'* The figures of adult wings are 

 pen drawings made from the permanent mounts with the aid of 

 the camera lucida or projection apparatus. 



4. In a saturated solution of Potassium Oxalate. 



