NORTH AMERICAN PSYLLID^E. 71 



Of the genera described, only one, Trioza, has thus far been 

 found in North America, but this genus is represented by numerous 

 species. The venation of the front wings offers good characters 

 for groups, while specific characters are best expressed in the genital 

 armature of the male. Two species from Florida exhibit very re 

 markable structural characters which justify the establishment of two 

 new genera here characterized. 



In the following descriptions I have used those orismological 

 terms which seem least likely to confuse, chiefly following Fr. Low 

 and other continental authors. The width of the head includes 

 the eyes, and length measurements are from vertex to tip of closed 

 wing. 



Sub-family PSYLLIN^E. 

 PACHYPSYLLA, new genus. 



Body very robust, transversely and longitudinally convex; in some species 

 glabrous, in others finely pruinose with exceedingly short and sparse pubescence. 

 Head large, vertical, vertex rugoso-punctate, longer than usual, but slightly 

 or not at all narrowed anteriorly ; anterior marginal line well marked, straight ; 

 frontal cones not in the same plane as the vertex, more or less oval, pubes 

 cent, vertical, about half as long as the vertex ; anterior ocellus not visible 

 from above; discoidal impressions punctiform or foveiform (c. -gemma) ; antennae 

 as long as (or even shorter than) the width of the head, stout, intermediate joints 

 sub-turbinate. Pronotum of usual length (short in c. -gemma], steeply ascending 

 posteriorly, rugosely punctate, of equal width, lateral impressions well marked, 

 front and hind margins gently curved ; dorsulum less developed than in the true 

 Psyllas, more than twice as broad as long ; sculpture of dorsulum and mesonotum 

 varying according to species, either nearly smooth (c. -gemma] or alutaceous (c.-ve- 

 mtsta) or rugoso-punctulate (c. -mamma and the rest of the species). Front wings 

 varying in length and form according to species, flat (less so in c. -gemma), sub- 

 membranaceous, and not rugose in the majority of the species (more leathery and 

 rugose in c. -gemma], pterostigma more or less distinct, tip of wing between radius 

 and fourth furcal and nearer to the costal than to the inner margin ; petiolus 

 cubiti much shorter than the discoidal part of the subcosta ; marginal cells unu 

 sually long, narrow (less so in c. -gemma), and of nearly equal size. Metasternal 

 processes shorter than in Psylla. Genital plate of male broad, convex at the sides, 

 slightly lobed posteriorly, forceps simple ; genital plates of female simple, oi 

 varying length. Legs stouter than usual. Larva and pupa with spinous tip of 

 abdomen and sides of body not acute. 



