NORTH AMERICAN PSYLLID^. 73 



cals terminating very obliquely upon the margin, the first slightly shorter than the 

 fourth, the second one-fourth longer than the first, which terminates at about the 

 middle of the inner margin ; stem of second fork as long as the third furcal ; tip 

 of wing distinctly between the radius and the fourth furcal ; outer basal cell one- 

 fourth shorter than radial cell ; second marginal cell as long, but not quite as wide, 

 as first marginal cell ; margin of cubital cell as long as that of second marginal. 

 Metasternal processes nearly twice as long as wide, constricted at base, apex not 

 sharply pointed ; legs yellowish gray, femora usually with the upper edge and a 

 sub-apical spot blackish, claw -joint black. ^ : genital segment as long as the two 

 preceding ventral segments together, wider than usual ; color, yellowish brown, 

 shining, with sparse, long pubescence ; plate nearly as high as the length of the 

 segment, wide, rounded and convex at the sides, provided with a distinct lateral 

 lobe ; anterior margin straight, posterior margin forming a nearly semi-circular 

 line, greatest width at apical third ; on its outer face the plate is convex and 

 smooth anteriorly ; the posterior lobe is rugose, and separated from the plate itself 

 by a wide and shallow depression. Forceps two-thirds as high as the plate, 

 front margin straight, hind margin slightly sinuate at basal half, tip rounded, outer 

 face smooth and very shining. 



9 : genital segment a little longer than the rest of the abdomen, opaque, brown 

 ish yellow with black markings, with moderately short and inconspicuous pubes 

 cence, upper plate gradually tapering apically and drawn out in a very sharp 

 point, which is slightly turned upward ; lower plate a little shorter than the upper, 

 rapidly narrowing from the base and pointed at tip, but by no means as sharply 

 as the upper plate. 



Described from numerous specimens reared from a large woody 

 gall formed on the petiole of the leaf of Celtis, a part of the base 

 of the leaf being included, so as to form a groove on one side. 



Pachypsylla celtidis-mamma (Riley.) 



Average length, 4 mm. Color dirty yellowish-brown, frequently dark brown 

 or brownish-yellow, upper side usually with a greenish tint ; antennae and legs 

 yellowish, variegated with black; wings subhyaline and whitish, speckled with 

 brown. Head and thorax more strongly rugoso-punctate than in venustu, opaque 

 and with sparse, extremely short, but glistening pubescence. Vertex as in the 

 preceding species, frontal cones more transverse; antennae a little shorter than 

 the width of the head, coloration and relative length of the joints as in venusta, 

 intermediate joints more distinctly turbinate. Parts of thorax formed and colored 

 as in venusta, a little less convex, and the brown color more predominant, with 

 markings on dorsulum and mesothorax less clearly defined. Front wings nar 

 rower and, therefore, apparently longer than in vemista, very little wider at ter 

 minal third than at basal third ; costal margin at base but slightly convex, at tip 

 more broadly rounded ; whitish, subhyaline, more or less densely covered with 

 small, brownish, scale-like specks, as follows : an oblique and gradually narrow 

 ing band (extending from tip of pterostigma to near tip of radius), which runs 

 across the wing to the tip of the first furcal, is usually freer from these dots than 

 the rest of the wing, while its edges are usually more crowded with the dots, so 

 as to bring the pale band into greater relief; quite frequently there is an intensi 

 fied patch of brown about discoidal part of subcostal vein and at all vein furca 

 tions ; also, the terminal space outside the^ pale oblique band is often uniformly 

 dark, but with three marginal pale spots (bne in each of the cubital, second mar 

 ginal, and discoidal cells) always more or less distinctly relieved. This pale band 

 is sometimes obsolete and the wing more or less evenly speckled ; exceptionally, 

 both inside and outside the oblique band, there is a border of variable extent, of a 

 uniform dark brown color, not composed of small dots ; pterostigma distinct, mod- 



