622 



Although in an early stage there is no doubt but that these 

 structures are supernumerary wings such as have been found in the 

 imagines, this case differs from almost all of the recorded cases in 

 being bilaterally symmetrical and in being closely similar to the 

 normal wing in its general outline. 



It would be very desirable to know how these abnormal wings 

 originated but the present case gave no clue as to their rise. One 



HDßM AL 



HDRM- 



ALS- 



CTA 



Fig. 3. P. rapne. Transverse section through supernumerary wing of right side. 



HDRM, AL, hypodermis of normal wing. HDRM, hypodermis of body wall. 



A LS, supernumerary wing. CT A, cuticula. B. & L. 1/5 i" obj. 2 in oc. 160 mm. 



point of interest was the apparent reflection of the two layers of the 

 hypodermis of the normal wing on the layers of the abnormal one. 

 This was not so clearly demonstrated as could be wished on account 

 of poor preservation (the specimen was killed in Picrosulfuric acid 

 mixture) but indications of this reflection were so frequent, although 

 never covering wide areas, that it is probable that the abnormal wing 

 was nearly if not a complete reflection of the normal structure. 

 Yellow springs, Ohio, U. S. A., June 25, 1901. 



