92 INSECUTOR INSCITI^ MENSTRUUS 



the posterior margins of segments 4-8 prolonged into a series 

 of oblique, postero-laterally-directed acute teeth. 



Type : Perissothrips parviceps, new species. 



The unusual features of the single species for which this 

 genus is erected are the small size and extreme shortness of 

 the head, the great length of the mouth-cone, the armed fore 

 tibia, and, in the male, the armature of the intermediate ab- 

 dominal segments. The first two characters and the acutely 

 pointed abdomen ally it closely with the North American 

 Chilothrips, with which, however., it can not be confused. 



Perissothrips parviceps, new species. (PI. Ill, figs. 3-6.) 



Female {macro pterous) . — Length about 0.9 mm. Color 

 uniform straw yellow ; antennse with segment 4 gray in apical 

 half and segments 6-8 dark brown, 5 sometimes grayish at 

 tip; wings lightly clouded with yellowish. 



Head nearly twice as wide as median dorsal length, broadest 

 basally, cheeks nearly straight, slightly diverging behind ; 

 occiput with two or three faint anastomosing lines ; inter- 

 ocellar and anteocular bristles small and inconspicuous. Eyes 

 very minutely setose, about three times as long as their distance 

 from posterior margin of head, and wider than their interval. 

 Ocelli equal in size, the posterior pair slightly more widely 

 separated than their distance from anterior ocellus; pigment 

 bright red. Antennae (PI. HI, fig. 3) about 3.7 times as long 

 as head. 



Prothorax about 2.84 times as long as head, sides slightly 

 convex and diverging posteriorly, where it is 0.9 as wide as 

 the median dorsal length ; posterior angles with one pair of 

 short bristles; surface smooth. Wings of fore pair with 

 about 18 bristles on costa ; anterior vein with a basal group 

 of three bristles, followed closely by another group of three, 

 and then by three widely separated ones in apical half ; pos- 

 cerior vein with an equidistant series of four. Legs short and 

 stout ; fore femora swollen, fore tibise angulate at apex within 

 ind with a small bristle arising from the apex of the angle. 



Abdomen about L4 times as wide as prothorax, smooth. 



