616 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 
not quite attaining apex of second abdominal joint, those of under wings slightly 
projecting Internally and posteriorly. A.bdomea oomposed of eight joints, widest at 
middle, gradually nun-owing anteriorly and very strongly posteriorly; anal joint 
drawn out in a horny process ; first joint very short, second twice as long as the 
first, the following three joints still Longer, the fourth being the longest and widest. 
dorsal and ventral sides of joints 2 to 1 separated by a rounded lateral lodging; 
dividing sutures of segments l to .") very deeply impressed; last three joints much 
. Btinotly divided, more horny, and of darker color, rapidly narrowing po 
orly, and provided dorsally with a number of black, backwardly directed, triangular 
teeth, arranged US follows: Sixth joint at middle of hind margin with two or three 
very small teeth placed transversely and with no lateral teeth; seventh joint at 
middle of hind margin, with a transverse row of four teeth, and on each side with 
two or three (often obsolete) teeth or tubercles : anal joint with the horny process 
about half as long as the joint, and nicked at the tip, while at base of process on 
each side a lateral row of four small, closely placed teeth extends to the tinder 
side, and finally on the disk of the joint three teeth triangularly placed, the poste- 
rior being the largest ; behind this group and just ab ove the base of the process is 
another tooth nicked at tip. 
The pupre of the other species differ mainly from the above descrip- 
tion in the smaller size, the form and length of the anal process, and in 
the number and arrangement of the abdominal teeth. That of P. 
c-gemma alone has some other distinguishing characters. 
The young larvae of all species are of a more uniform pale color with 
less developed wing-pads and the segmentation of the abdominal joints 
much less evident; they are further distinguished by the smaller num- 
ber of autennal joints and the weaker development of the abdominal 
armature. 
The galls produced by the species of Pachypsylla may be distin- 
guished as follows: 
Polythalamous (very rarely monothalainous) galls, never on the surface of the leaf, 
always singly. 
Large gall on petiole and involving the basal portion of the leaf; usually some- 
what reniform in shape, and with an opening near the tip. 
P. venusta O. S. 
Smaller gall on the twig, bud-shaped, and without opening. 
P. c. -gemma Riley. 
Monothalarnous galls, always on the leaf, usually occurring in great numbers. 
Gall blister-like on both sides of the leaf and hardly raised above the surface of 
the leaf P. c.-vesictilnm n. sp. 
Gall on the under side of the leaf, not blister-like, more or less raised above the 
surface aud assuming various shapes. 
Gall on npper side of leaf, blister-like and not forming a depression; on 
undersideof leaf star-shaped or flower-shaped.. P.O. -asUriscusu. sp. 
Gall on upper side of leaf represented by a depression. 
Gall on upper side of leaf, with the outer rim alone depressed, the 
central portion slightly raised and provided with a median spine; 
on under side of leaf wart-like, much flattened, with a more or 
less pronounced depression at middle P. c. -umbilicus n. sp. 
Gall on npper side of leaf represented by a cup-like depression, the outer 
rim sometimes elevated. 
Gall very large, mammiform without depression or rim on top, 
usually not pubescent, sometimes with slight down at base. 
P. c. -mamma Riley. 
