HACKBERKY PSYLLIDS. 615 



and not longer than the width of the head ; pronotum and dorsulum 

 strongly ascending and rugosely punctate ; anterior wings of varying 

 form and consistency, but never hyaline ; pterostigma present ; tip of 

 wing between radius and fourth furcal ; marginal cells unusually long 

 and narrow ; genital plate of male more or less oval (when viewed 

 from the side) and not linear. 



The genus belongs to the subfamily PsylliucTe and has no equivalent 

 in the European fauna ; but some allied, still uudescribed, genera occur 

 in the New World. 



The species of Pachypsylla are divisible into the following groups, 

 the table being reproduced from my " Notes on North American Psyl- 

 lidaB" (1. c, 75): 



Head and dorsum opaque; front winga aubmembrauaceous or snbhyaline, not rugose; 

 pterostigma distinct ; both marginal cells very long, narrow, and of about 

 equal size in length ; anal style of full-grown larva and pupa long. 

 Dorsulum and mosonotum alutaceous, glabrous ; front wings narrowly rounded 

 at tip, widest in basal half; genital segment of female longer than the rest 

 of the abdomeu ; anal style of full-grown larva and pupa notched at tip. 



Type, venusta. 



Dorsulum and mesonotum rugoso-punctate, with distinct but very short, sparse 



pubescence; front wings broadly rounded at tip, widest in terminal half ; 



genital segment of female shorter than the rest of the abdomen ; anal style 



of full-grown larva and pupa pointed at tip Type, c.-mamma. 



Head and dorsum shining, without pubescence ; front wings somewhat convex, basaJ 

 half not wider than terminal half, broadly rounded at tip, distinctly rugose; 

 pterostigma indistinct ; marginal cells less narrow, the first shorter and some- 

 what smaller than the second ; genital segment of female shorter than the 

 rest of the body ; anal style of full-grown larva and pupa very short, nicked 

 at tip Type, c.-gemma. 



For P. G.gemma I have suggested the subgeneric name Blastophysa, 

 but the yet uudescribed species are all so closely allied to P. c.-mamma 

 that they can only be distinguished with difficulty. 



The distinguishing characters of the pupa, which apply also to the 

 full-grown larva, have been alluded to in the above table, and aside 

 from these characters the following description, taken from the pupa 

 of the largest of our species will, in the most important points, also 

 apply to those of the others pecies : 



Pupa. — Broadly oval in outline ; widest at middle of abdomen : depressed anteriorly ; 

 abdomen more convex. General color faint bluish-green ; upper surface with indis- 

 tinct rosaceous markings ; autennie and legs pale yellow ; wing-pads and tip of abdo- 

 men brownish ; abdominal spines black. Sculpture not obvious, surface opaque, 

 thinly covered with loug, soft, whitish and not clavate hairs, which are more numer- 

 ous on the abdomeu, but which do not form a fringe as seen in other genera. Upper 

 and under sides of body somewhat sharply divided, but the sides everywhere rounded 

 off. Head (including eyes) as wide as the mesonotum at middle; much less inclined 

 than in the imago ; anterior margin broadly rounded ; frontal lobes not indicated ; 

 eyes very large, globular, finely granulated, reaching to the hind margin of the 

 head; ocelli barely visible from above, antennse thicker than in imago, and, there- 

 fore, apparently shorter, but otherwise not difl'erent ; pronotum separated from head 

 by a deep sulcus, not different in shape from that in imago ; dorsulum much shorter 

 than in imago; mesonotum as in imago. Wing-pads smooth, very shining, slightly 

 diverging posteriorly, small and narrow in comparison with those of other genera, 



