NORTH AMERICAN PSYLLID^E. 75 



as, or a little longer than, the basal portion ; radius nearly straight, third and fourth 

 furcals of nearly equal length, terminating very obliquely upon the margin, stem 

 of second fork a little longer than third furcal, first furcal but little longer than 

 the stem of the first fork and one-third shorter than the second furcal, which is 

 but little longer than the fourth furcal ; outer basal cell very large and nearly as 

 long as the inner one ; base of pterostigma nearer to the middle than to basal 

 third of wing ; first furcal terminating at about the middle ; margin of first mar 

 ginal cell as long as that of second; mai'gin of cubital cell shorter. Abdomen in 

 matured specimens dark gray, each segment bordered behind with roseate color, 

 iri immature specimens brown or brownish-yellow. Metasternal processes pale- 

 green, elongate oval, obtusely rounded at tip. Femora usually brownish-yellow, 

 sometimes blackish, with exception of the tip ; tibiae and tarsi black. 



<^: genital segment somewhat longer than the preceding ventral segment; plate 

 as high as the length of the segment, anterior margin straight, posterior lateral lobe 

 very feebly indicated toward the tip, the plate, therefore, slightly wider at tip than 

 at base, posterior edge slightly curved, tip truncate ; the lobe is hairy, opaque, 

 rugose, and divided from the main part of the plate by a longitudinal depression ; 

 forceps three-fourths as high as the plate, anterior edge slightly convex, posterior 

 edge slightly concave, tip acute. 



9 : genital segment somewhat longer in proportion to the rest of the abdomen 

 than in c. -mamma, but otherwise not different. 



Described from numerous specimens reared from a small, rounded, 

 more or less irregular swelling of the bud of Celtis. 



The species shows sufficient differences, as compared with the more 

 typical Pachypsylla, to warrant separation into a sub-genus, which 

 I would designate by the name of Blastophysa, and which in future, 

 with increased material, will probably be accepted as a good genus. 



The following dichotomic table gives the principal differences 

 between the three species of Pachypsylla just described : 



Head and dorsum opaque ; front wings submembranaceous or subhyaline, 

 not rugose ; pterostigma distinct; both marginal cells very long, narrow, 

 and of about equal size and length ; anal style of full-grown larva and 

 pupa long. 



Dorsulum and mesonotum 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 top venusta. 



Dorsulum and mesonotum rugoso-punctate, with dis 

 tinct 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 c. -mamma. 



Head and dorsum shining, without pubescence ; front wings 

 somewhat convex, basal half not wider than terminal half, 

 broadly rounded at tip, distinctly rugose ; pterostigma indis 

 tinct; 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 c.-gemma. 



