ON 



THE OSMYLIN^E OF JAPAN. 



Plethosmylus hyalinatus Krüger, Stett. Ent. Zeit., 74 Jg., p. 274 



Head bright yellow without marking ; mouth-parts and clypeus 

 somewhat darker ; ocelli minute and placed very close together ; 

 antennae black. 



Prothorax blackish, variegated with yellow ; above three some- 

 what yellowish longitudinal lines, of which the median is the broadest. 

 Meso- and metathorax fuscous black with pale hairs. 



Legs pale yellow ; tarsal joints suffused with fuscous ; claws 

 commonly serrate internally, rarely without the serration ; coxa I has 

 a rather long spur which is however not so long as in O. maculatus 

 of Europe. 



Abdomen blackish with pale hairs, yellowish at apex. The boat- 

 shaped organ depending from the last abd. segment in the female 

 yellowish, more or less darker along the margin. 



spots. Neuration mostly blackish or fuscous ; subcosta and radius 

 yellowish, though sometimes pale or dark greyish. 



Most costal cross-veins are furcate, except several basal ones, 

 which are simple ; here and there two adjoining furcate veins cross 

 each other or are united by a short cross-vein ; radial sector with 

 10-14 branches; two series of gradate veinlets complete and nearly 

 parallel. 



Hindwing hyaline, with brownish pterostigma. 



(1913). 



Fig. 8. 



Coxa I of Osmylus hynlinatus 

 M'L. 20 x . 



Forewing broad, subacute at 

 apex, hyaline with a grey tinge ; 

 commonly without spot, sometimes 

 with a small discal spot and some 

 more spots near apex ; outer series 

 of gradate veinlets often narrowly 

 margined with faint fuscous ; inner 

 marginal area occasionally clouded. 

 Pterostigma with some dark fuscous 



