132 Buiìctiu di' Id Société Royale Entomologifjiie cVEgyjìte 



wide; V. joint 0,07 mm long, 0,028 mm wide ; 

 VI. joint 0,06 mm long^ 0,029 mm wide; VII. joint 

 o,o5 mm long, 0,022 mm wide; VIII. joint o,o3 mm 

 long, 0,01 mm wide. Head 0,26 mm long, 0,21 mm 

 wiide. Prothorax 0,18 mm long, o,36 mm wide (across 

 fore coxae). Fore femora 0,22 mm long.^ 0,10 mm 

 wide; fore tibiae (incl. tarsi) 0,28 mm long, o,o5 mm 

 wide. Pterothorax o,/lo mm long, 0,42 mm wide. Mid- 

 dle femora 0,19 mm long, 0,06 mm wide; middle 

 tibiae (incl. tarsi) 0,28 mm long, o,o/j mm wide 

 Hind femora 0,2/i mm long, 0,06 mm wide; hind 

 tibiae (incl. tarsi) o,33 mm long, o,o4 mm wide. 

 Length of wings (without fringe) 0,8 mm. Abdomen 

 (incl. tube) 1,3 mm long,/o,/} mm wide. Length of 

 tube 0,17 mm, width at base 0,07 mm, at apex 

 0,0/i mm. — Total length 1,7-2,2 mm. 



I have allowed nmyself the pleasure of naming this 

 new species after its discoverer, the well-known Thy- 

 sanopterologist Mr. C. B. Williams. 



G. williamsi is closely allied to G. ebneri, diverg- 

 ing by coloration of antennae and by the clear, hyaline 

 fore wings furnished with dupicated fringe-hairs. 



As Mr. Williams infoi ms me, this species was 

 taken from oììc and the same tree and apparently 

 from the same type of galls as G. ebnen. 



