1902.] 151 



been small, or that sex has passed off before the other. Whatever 

 may be the cause, the practical result is that one has frequently to 

 determine the species of Apatania from females alone, and this is none 

 too easy for the reasons given in the opening paragraph. 



When on the Dovrefjold in 1900, L took a number of specimens, 

 exclusively females, which I could not determine satisfactorily, and I 

 have just passed through my hands a much larger collection, made by 

 Herr Embr. Strand, during the past summer in Arctic Norway. The 

 latter collection included numerous males of Apatania stigmatella, 

 Zett., but there were present many female examples which were 

 evidently not of that species ; and even amongst the females which 

 were associated w r ith A. stigmatella from the same locality, there were 

 one or two as to which I could not satisfy myself that they belonged 

 to that species. At this point it occurred to me to try a method 

 employed by Dr. Kis, in connection with the study of the smaller 

 Pcrlidee, namely, preparing the bodies as microscopic objects by rapid 

 boiling for a minute or two in caustic potash, whereby shrivelled up 

 bodies are practically restored to their original forms. I did not 

 expect more than to get a better idea of the form of the vulvar scale 

 and of the external plates of the apex of the abdomen, and I was 

 accordingly pleased to find that in addition to the restoration of 

 form the preparations showed an elaborate internal apparatus of rods 

 and plates, no doubt connected with the process of oviposition. As 

 this apparatus was strongly chitinized, the possibility of its varying in 

 shape in the different species at once suggested itself. A number of 

 preparations of all the available species were then made with a result 

 that was satisfactory, and the object of the present paper is to give at 

 least a preliminary idea of the structure referred to. I have neither 

 the time nor the knowledge to allow me to discuss the true nature and 

 functions of the apparatus, and what I have to say concerning it is 

 entirely from the point of view of helpiug towards a surer basis for 

 the determination of the females of the species concerned. As the 

 female of A. stigmatella has not to my knowledge been previously 

 figured, the information I give here regarding it may, of itself, give 

 some little value to these notes. 



Walleugren divides the genus Apatania into two subgenera, 

 Apatania and Apatelia : — 

 A. Sub-costa and radius of the hind-wings near their outlet into the fore margin 



considerably separated from each other Apatania. 



AA. Sub-costa and radius of the hind-wings near their outlet into the fore margin 



running together or crossing each other Apatelia. 



