( cli ) 



find a simple but effective apparatus ; it is particularly note- 

 worthy to see that the specialisation is towards extreme 

 simplicity, and I think proves a high degree of development. 

 With the exception of the following genus {Lyniantria) we 

 have here the simplest form of genitalia that I have yet 

 discovered among the Lymantriadae- — of course there are 

 many genera that I have not at present had the opportunity 

 of examining. 



In antiqua the cingula is a simple collar expanding outwardly 

 in the tergite ; the tegumen is an uncal horn-like sclerite, 

 curved slightly downwards ; the harpagones are broadish 

 lobes curved and tapering smaller towards the apex, clothed 

 with fine short hairs, the upper margin being produced for- 

 wards and upwards into a strong highly curved hook; the 

 sedceagus is shortish, somewhat irregular in shape, with the 

 apical third expanding outwardly. 



Lymantria novaguinensis, B.-B. 



This is the simplest in form of all the genera I have yet 

 examined in the Lymantriadae. I figure this species as it 

 shows best the form and position of the genitalia, and others of 

 the genus including monacha confirm it. 



The cingula is a simple collar with a small saccus ; the 

 tegumen is a large curved horn-like sclerite ; the harpagones 

 are short and broad, produced a little above the middle line 

 into a longish digital spike ; the sedceagus is of moderate size, 

 largest at the base and tapering to the apex. In some species 

 the sedoeagus is comparatively speaking quite a fine tube. 



The Lasiocampidae show marked atavism in their armature, 

 the only progressive character being that the sternite and 

 tergite sections have not retained their complete set of organs, 

 such as I consider all primitive forms probably had. (" Complete 

 set of organs," this is a descriptive phrase, to express a difference 

 well known to anatomists of these parts, and intended to convey 

 the distinction between the highly specialised and simple 

 organs prevalent in most Rhopalocera and some Heterocera, 

 consisting of the cingula, the tegumen and anus, the harpa- 

 gones and sedoeagus, combined with the complete disap- 

 pearance of the sternite and tergite ; in comparison with the 



