54 PROC. ENT. SOC. WASH., VOL. 23, NO. 3, MAR., 1921 



Extreme width of head, 3.1 mm. 



Cranium?- narrower than prothorax, its extreme width in proportion to the 

 extreme width of prothorax being 2:3; transverse with width to length as 2:1.5, 

 widest immediately behind antennae; surface finely reticulate. 



Frons, (fig. 18) indistinctly limited, wider than long, with width to length as 

 3:2; frontal suture with anterior half slightly convex, posterior half slightly con- 

 cave; posterior frontal angle shortly accuminate. Anterior margin with four 

 setae, two are exteriorly placed, between articulation of mandible and base of 

 antenna; two are interiorly placed, between articulation of mandible and median 

 line of frons; behind and close to the two exterior marginal setae is one seta; 

 behind the interior marginal setae and towards the middle of frontal suture is a 

 short series of three setae. 



Epicranial suture, in proportion to length of frons as 1:3; elevation of margin 

 along epicranical suture slight and dark colored; epicranical setae are about seven 

 in series along the frontal suture and about ten in an irregular group laterally 

 from antennal base to a point almost at the level with posterior angle of frons 

 (figs. 12 and 18). 



Clypeus, about two and a half times as wide as long, trapezoidal; in front with 

 a transverse, slightly lighter colored, naked, ribbon shaped region, limited 

 posteriorly by a low ridge; behind the ridge two lateral setae and one seta 

 between anterior lateral seta and longitudinal middle line of clypeus. 



Labrum, with length to width as 1:1.5, and with length to length of clypeus as 

 1:0.75, not much narrower than clypeus; laterally rounded, anterior margin 

 irregularly and slightly crenulate, medianly somewhat obtusely produced; 

 dorsal surface roughened with numerous small, rounded projections; posteriorly 

 slightly elevated, flatly descendent forward; lateral border (fig. 7) ventrally 

 flattened, with rather dense transverse striation; at apical margin (fig. 18) with 

 one well developed and one rather small seta; at lateral margin dorsally with a 

 series of about five setae and ventrally with a series of almost as many short, 

 curved setae as striations; close to and parallel to posterior margin with a series 

 of four setae; on disk with two setae, one placed anteriorly, one larger near the 

 transverse middle line. 



Antenna, almost as long as cranium, rather slender, four jointed; basal joint 

 clavate, about one-fifth the length of entire antenna; prebasal joint clavate, 

 about twice as long as basal joint; subapical joint about same length and pro- 

 portions as basal joint, but anteriorly on the inner side produced into a well 

 developed accessory process of pointed conical shape; apical joint somewhat 

 shorter than first joint, twice as long as thick, elliptical, anteriorly pointed; a few 

 setae on prebasal joint; thin, semitransparent sensorial area on apical joint of 

 accessory process. 



Mandible, slightly longer than cranium. Scissorial portion (s fig. 18) three 

 times shorter and approximately half as wide as rest of mandible, depressed, 

 above smooth, below rugose with longitudinal groove along exterior margin, and 

 a shallow cavity at base (figs. 8 and 18); cutting edge thin with terminal angle 

 pointed and posterior angle obtuse, separated by small incision from minute 



J The term cranium is here used for the capsule, formed by the two fixed parts 

 of the head, frons and epicranium. 



