British species of Pst/I/ic/ce. 531 



Species with the costal stigma obsolete or almost obsolete : 

 Forsteri, alni, huxi, S])n7'tio])hila, hippo- 

 pha'e's. 



„ with the elytra more or less yellowish or tes- 

 taceous: Forsferi, bnxi, hippophaes, spartio- 

 philn, sylvicola, I^iiirii. 



„ Avith brown elytra: pruni. 



„ Avith dark clouds or patches between the nerves : 

 pyri. 



„ with a black or dark streak along the dorsal 

 margin next the apex of the clavus: salicicola, 

 rhamnicola. 



,, spotted round the apex : costatopiinctata,ferru- 



flinea. 



„ Avith a black band before the apex : fraxini. 



Species 1. Psylla Forsteri. 



Psylla Fiirsteri, Flor, Rhyn. Li\d. ii. 458, 2 ; Leth. 

 Hem. Xord, ed. ii. 88, 2; Psylla Alni, Forster, 

 Verb. Ver. Rheinl. v. 70, 1. 



Pale green, yellow or greenish-yelloAv. Face: lobes 

 short, sparingly clothed Avitli fine pale hairs, and AAuth one 

 long one projecting from the apex. Antennce \Qvy long, 

 4 — 8 joints gradually groAving more broadly black at the 

 apex; 9 — 10 black. Elytra flxintly testaceous or almost 

 clear, transparent; costal nerve frequently bright green. 



Head : croicn very broad, posterior margin deeply con- 

 cave. Face: lobes short, sparingly clothed Avith fine pale 

 hairs ; about as long as the croAvn doAvn the centre ; cone- 

 shaped, Avith a long, stoutish hair projecting from the apex ; 

 base broad. AntenncB very long, clothed Avith very short 

 somcAvhat erect hairs ; 4 — 8 joints gradually groAving more 

 broadly black at the apex; 9 — 10 black; 4th about tAA'O- 

 thirds the length of the 3rd; 5 — 6 subequal; 7th longer 

 than the 3rd. 



Thorax: pro- and rneso-notum pale green, yellow or 

 greenish-yellow. Elytra faintly testaceous, sometimes 

 almost clear, transparent ; nerves entirely yelloAv or Avith the 

 costal margin bright green ; stigma almost obsolete. Leys 

 pale green or yelloAv. Tarsi: 2nd joint broAvnish. Claws 

 dark broAvn. 



Abdomen pale green, or green ish-yelloAv. 



Length 5 If, ? 2^ lines. 



This species stands next in size to P. Alni, from which 



