HACKBERKY PSYLLIDS. 615 
and not longer than the width of the head ; prouotnm and dorsulum 
strougiy ascending and rngosely punctate ; auterior 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 Psyllinae and has no equivalent 
in the European fauna ; but some allied, still undescribed, 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- 
lidae" (1. c, 75): 
Head and dorsum opaque; front wings submenibranaceous or subhyaline, 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 loug. 
Dorsulum and niosonotura alutaceous, glabrous; front wings narrowly rounded 
at tip, widest in basal half; genital segment of female longer than the rest 
of the abdomen ; anal style of full-grown larva and pupa notched at tip. 
Type, venuata. 
Dorsulum aud 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.-m.imma. 
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. c. gemma I have suggested the subgeneric name Blastojphysa, 
but the yet undescribed 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-greeu ; upper surface with indis- 
tinct rosaceous markings ; antennae 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 abdomen, 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, antennae thicker than in imago, and, there- 
fore, apparently shorter, but otherwise not different ; 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, 
