76 BIOLOGICAL SOCIETY OF WASHINGTON. 



Sub-family TRIOZIN^. 

 CEROPSYLLA, new genus 



Body moderately slender, slightly convex longitudinally, glabrous, impunctate, 

 opaque. Head with the eyes slightly narrower than the widest part of the tho- 

 rax ; vertex nearly half as long as wide, convex anteriorly, slightly emarginate 

 behind ; discoidal impressions large and polished, but shallow and ill-defined ; 

 frontal cones well separated from, and much depressed below, the plane of the 

 vertex, nearly vertical, a little longer than wide, about half as long as the vertex, 

 not divergent, not narrowing anteriorly, obtusely rounded at tip, jet black, opaque, 

 slightly pul^escent; antenna; more than twice as long as the width of the head, 

 thin, terminal joints distinctly broader, joint 3 as long as 4 and 5 together, the 

 last two joints less connate than usual, terminal bristle short. Thorax with the 

 pronotum very short, deeply emarginate behind, lower than the head, and almost 

 covered at the middle by the overlapping dorsulum ; dorsulum longer than wide, 

 anterior lobe much more developed than the posterior, laterally convex, gently 

 ascending posteriorly ; mesonotum nearly as long as dorsulum, of usual form. 



Wings flat, perfectly hyaline, not sculptured, two and one-half times longer 

 than wide, widest beyond the middle, outer costa gradually and slightly arched at 

 base, tip distinctly angulated ; basal part of subcosta unusually long, as long as 

 the branch of the Seconal fork ; the stems of the two forks not starting from 

 the same point of the subcosta, that of the first fork starting alone from the sub- 

 costa, some distance before the usual separation point of tlie principal veins ; dis- 

 coidal part of the subcosta extremely short — in fact, hardly perceptible ; thus the 

 radius, the radial part of subcosta and the stem of the second fork start from 

 nearly the same point; radial part of subcosta but little shorter than the stem of 

 first fork ; radius straight, unusually short — shorter than the basal part of the sub- 

 costa; stem of second fork running, at basal fourth, very close to the radius, 

 then gradually diverging from it ; tip of wing within second marginal cell, but 

 very close to the fourth furcal. which is nearly equal in length to ihe first and dis- 

 tinctly longer than the third furcal ; second furcal nearly twice as long as the third 

 and about as long as stem of the second fork. Basal cells very long, the outer 

 not quite attaining the middle of the wing, the inner reaching beyond the middle; 

 radial cell much shoiter than outer basal cell ; first marginal cell much larger 

 than the second, but of similar shape. 



Ceropsylla sideroxyli, new species. 



Average length, 4.2 mm. To the characters given above in the generic de- 

 scription but little remains to be added. The color is greenish-yellow on the 

 upper side, abdomen and under side more decidedly green ; dorsal marking of 

 brownish-yellow faintly indicated ; antennae black, with the three basal joints 

 pale yellow; legs yellowish-green or pale yellow. The wings are perfectly col- 

 orless and transparent, the veins very fine, blackish. The exceptional arrange- 

 ment of the venation, especially the almost complete absence of the discoidal part 

 of the subcosta, produces some curious results, viz., the basal part of the sub- 

 costa ana the radius appear to form a single straight line, and the discoidal cell is 

 triangular, with the angle towards the base of the wings narrowly produced. The 



