THE JUMPING PLANT-LICE OR PSYLLID^ OF THE NEW WORLD. 105 



Described from three males and two females from Virginia, October 

 9, 1881, on Sonchus arvensis; one male and three females from Wash- 

 ington, District of Columbia (E. A. Schwarz), June; many males, 

 females, and nymphs from Atlanta, Georgia (J, C. Bradley), July 6, 

 1909. 



Type.— C&t. No. 18094, U. S. Nat. Mus. 



The nymph of this species is distinctly triozine in form, being 

 bordered completely by a dense fringe of long, white, hair-like 

 processes, so characteristic of Trioza species. 



Head more or less deflexed, sometimes perpendicularly so ; vertex 

 quadrate, semicircular, or subtriangulate ; gense produced into vari- 

 ously shaped lobes or cones beyond end of vertex; frons covered 

 by gense, visible only as a very small sclerite bearing front ocellus. 

 Antennae typically ten-segmented, long or short. Thorax usually 

 well arched; sclerites of thorax variable, as described under tribes 

 and genera. Hind tibiae often with a spur at base, with five to twelve 

 black spines at apex; basal tarsal segment of hind legs with a pair of 

 black claw-like spines at apex. Wings variable from thick to hyaline 

 rhomboidal to elongate-ovate, seldom, if ever, ovate and at the same 

 time acutely angled at apex, as in Tnoza; media and cubitus always 

 with a petiole. 



There are grouped in this subfamily several genera not heretofore 

 associated together. Several genera formerly placed in Aphalaringe 

 have been transferred to this group because of ob^dously close rela- 

 tionships one to another. The relative length of the cubital petiole 

 CM-I-Cu) and the discoidal subcosta (R) has been the basis for sep- 

 arating certain of these genera into one or the other of Aphalarinse or 

 Psyllinae, but this character is of little value and often separates 

 widely two closely related species, or even two specimens of the same 

 species. 



A comparison of forms at opposite ends of the subfamily series 

 does not show any apparently close similarities, and yet with the 

 many intermediate forms before us, we readily see the inter-relation- 

 ships and similarities of the various genera. The group has been, 

 for convenience, divided into four tribes : Pachypsyllini, Euphyllurini 

 Arytainini, and Psylliai. 



The principal and most distiactive characters of this subfamily are 

 the concealed frons, the presence of genal cones or lobate processes, 

 the presence of the apical claw-like spiaes on the posterior basal tarsus 

 (not limited, however, to this group), and the presence of a cubital 

 petiole (M-t-Cu). The following synoptic table shows the relation- 

 ships of the tribes and genera to each other to a certain extent. 



