PEMPHIGUS. 113 



Genus XXVI.— PEMPHIGUS,* Hartig. 



Rostrum as in Schiz'oneura. 



Antennge short, with six joints, omitting the nail- 

 like process. Third joint about equal to the three 

 following taken together. The third, fourth, and fifth 

 joints commonly ringed ; the sixth joint longer than 

 that of Schkoneura. 



Cornicles wanting. 



Wings with no furcated cubital vein ; this vein, as in 

 the last genus, being unattached to the cubitus ; stigma 

 large and trapezoidal ; the two oblique veins usually 

 start from the same point. The posfc-costal nervure 

 of the hind wing somewhat angular, from which angle 

 the two oblique veins spring. 



Legs short, particularly in the apterous forms. 



It is to be noted that sharp characters cannot always 

 be drawn from minute differences in the antenna! 

 joints. These organs become developed during the 

 progress of the insect towards its imago state, for here 

 it is that the climax seems to be reached and not in 

 the true sexes. These last suffer a degradation in 

 type, which appears in the stunted antennse and total 

 absence of efficient buccal organs. 



Neither can any safe characters be made from the 

 deflexed or vertical position assumed by the wings 

 whilst at rest. The horizontal and pent-wise position 

 has been before noticed in some of the foregoing genera. 



Pemphigus fusgifrons, KocJi. Plate CX, figs. 6 — 9, 



Amycla fusci/rons, Koch. 

 Fem])higus JBoyerii Pass. 



„ ?:ece maidis, Low. ? 

 Ai^liis radicum, Boyer de Fonscolombe ? 



* From TTfjit^if, tyoe, a bladder or pustule. 



