British species of Psyllidce. 543 



crown down the centre ; base broad, sides sloping to the 

 middle ; from thence to the apex gently inclined. Antennce 

 yellow ; 9 — 10 joints black, or sometimes the last four 

 dark brown. Elytra transparent, very faintly testaceous ; 

 nerves pale ; costal stigma widish at the base, and termi- 

 nating about in a line with the apex of the upper arm of 

 the cubitus. 



Head: (?ro?o?z, posterior margin slightly concave. Face: 

 lobes somcAvhat long, divergent at the apex, about as long 

 as the crown down the centre ; base broad, sides sloping 

 to the middle, from thence to the stumpy or slightly 

 rounded apex gently inclined, inner margin somewhat 

 straight. Antennce. yellow, reaching to about the base of 

 the radius; 9 — 10 joints black, or sometimes the last four 

 dark brown, 4th about two-thirds the length of the third. 



Thorax : pro- and meso-notum green, yellow, red or 

 brown-red, sometimes the latter, with very indistinct 

 indications of pale longitudinal lines. Elytra transparent, 

 with a very faint testaceous tinge ; nei"ves pale, varying 

 slightly in depth of colour, according to that of the indi- 

 vidual ; costal stigma widish at the base, and terminating 

 about in a line with the apex of the upper arm of the 

 cubitus. Legs yellow ; in dark coloured examples some- 

 times the thighs brownish ; tihice, apex and tarsi brown. 



Abdomen above green or red, or brown-red ; in the 

 latter case generally the posterior margins of the segments 

 pale, sometimes the entire abdomen black. 



Length 1| line. 



The var. rubida, Meyer-Diir, somewhat resembles 

 P. salicicola, but it is smaller in size than the last- 

 named, which has, in addition to the differences in the 

 antenna and frontal lobes, a short dark streak at the apex 

 of the clavus. 



Not uncommon from June to the end of August on 

 various trees; amongst others I have taken it on birch 

 and whitethorn. 



Species 14. Psylla viridissima. 



Bright green. Face: lobes longer than the crown down 

 the centre; base broadish; apex somewhat acute; outer 

 margin concave; divergence at the apex about equal to 

 the base of either. Elytra clear, transparent, 2^ times as 

 long as broad ; nerves fine ; costal stigma moderate. 



^eat? bright green. Crotcn: posterior margin concave. 

 Ocelli reddish or orange red. Face : lobes bright green. 



