British species of Psyllidce. 549 



sloping gently ; from thence to the apex knoblike ; diver- 

 gence about equal to one-half the base of either of them. 

 AntenncB yellow ; 4 — 5 at the apex broadly black, 6 — 10 

 black. Elytra clear, transparent ; nerves somewhat 

 brownish-yellow, or frequently rose-pink; apex darker; 

 costal stigma wide, long. 



Head: crown red or orange; apex narrowly pale yellowish- 

 white ; posterior margin concave. Face : lobes yellowish- 

 white or white, sparingly clothed -with pale hairs; exterior 

 margin sloping rapidly for two-thii'ds its length ; inner 

 margin sloping gently for the same distance ; from thence 

 to the apex knoblike, white ; round the base of the con- 

 traction is a fuscous ring. Aniennce yellow, reaching to 

 the base of the stigma ; 4 — 5 broadly black at the apex, 

 6 — 10 black; 4th three-fourths the length of the 3rd. 



Thorax : pronotum pale yellow or yellowish-Avhite, fre- 

 quently with a fine, more or less interrupted, red line across 

 the middle ; mesonotum red or orange ; anterior portion 

 with a more or less distinct pale central line; posterior 

 portion with four broad, longitudinal, red-brown streaks 

 narrowly margined with pale yellowish-white. Elytra 

 clear, transparent; nerves somcAvhat brownish-yellow or 

 rose-pink as far as the bifurcation of the arms of the 

 cubitus, from thence to the apex darker ; costal stigma 

 wide, long ; dorsal margin at the base brownish-yellow, 

 prolonged into a black streak which terminates at the apex 

 of the clavus ; within the spaces enclosed by the nerves 

 and adjoining the apical margin is a small, almost obsolete 

 fuscous- stain. Leys yellow. Tarsi and claivs: 1st and 

 2nd pairs fuscous-brown; 3rd, second joint only and claws 

 fuscous-brown. 



Abdomen above more or less red or orange, with a 

 broad dark streak doAvn the middle in some examples; 

 $ genital segments greenish-yellow ; plate above brownish ; 

 processes yellow; apex narroAvly brown. 



Length 1^ line. 



This species belongs to the group in which are P. cos- 

 tatopunctata and P. ferruyinea, but it is larger than 

 either of these species, has different formed face-lobes and 

 genitalia, as also much less defined markings round the 

 apex of the elytra. 



The only specimens I have seen were taken by Mr. 

 Douglas and myself on the common buckthorn {Rhamnus 

 catharticus), at Sanderstead, in August. 



