22 U.S. NATIONAL MUSEUM BULLETIN 2 79 



especially in median i-egion. Postclypeus as dark oi' darker than 

 cranium, with 2 or 3 setae on each side. Preclypeus light yellow, 

 glabrous. Labrum (fig. 1) symmetrical, darker than preclypeus, with 

 paired median, lateral, anterolateral, and anterior setae. Lateral 

 margins evenly rounded to sharply angulate; anterior margin broadly 

 rounded to weakly bilobed or trilobed. Antennae (figs. 1 and 20) 

 three-segmented, terminal segment much reduced. Segment 2 with 

 prominent, distal sensory cone. Segment 3 with terminal sensory pegs; 

 all groups except terrestris group with 5 pegs and 1 seta (figs. 45 and 46) ; 

 terrestris group with 6 pegs (figs. 44 and 47). Epipharynx (figs. 2 and 

 3-8) with about 4 to 1 3 stout setae on each side of corypha. Clithra 

 present. Corypha with 4 prominent setae arising from marginal tu- 

 bercles. Haptomerum at least partially sclerotized, with central, 

 elevated, lightly sclerotized sensory area usually with 2 (4 in scaler 

 group) smaller sensory spots distad of 2 larger, setiferous sensory spots. 

 Haptomerum also with about 1 to 6 setae posterolaterad of sensory 

 area on each side. Setae often overlapping paria. Anterior border of 

 pedium usually with 4 (2 in scaler group) sensory spots distad of slightly 

 arching, transverse row of about 10 to 16 sensory spots. Pedium usually 

 with curving, continuous row of inwardly directed phobae near lateral 

 and anterior borders, anterior phobae proximad of sensory spots usually 

 very small; or pedium with slightly oblique row of inwardly directed 

 phobae along lateral border on each side, these rows usually joined 

 anteriorly by transverse row of reduced phobae proximad of sensory 

 spots. Variations of the above 2 basic patterns also occur. Pedium with 

 additional pronounced median, transverse patch of caudally directed 

 phobae. With a fused phobal mass on each side of pedium near poste- 

 rior border. Pedium often with smaller phobae mediad or proximad 

 of fused phobal masses, latter phobae usually more pronounced on 

 right side when present. Paria with posterior group of about 5 to 13 

 stout setae on each side near tormae. Tormae symmetrical; united 

 medially, with anterior epitorma and prominent pternotormae. 

 Haptolachus with 2 elevated, sclerotized plates flanking median, non- 

 pigmented, elevated area. Sclerotized plates unequal, left plate smaller. 

 Median elevated area with numerous phobae in area between sclerotized 

 plates; usually with 4 sensory spots posteriorly. Haptolachus also with 

 2 macrosensilla in membranous areas on each side of central elevated 

 area. Glossa (fig. 19) with 4 sensory spots and usually 4 to 6 setae 

 dorsally; with 2 sensory spots and 2 long setae ventrally. Labial palpi 

 two-segmented; basal segment with terminal, exterior phobal fringe, 

 Hypopharynx (fig. 19) divided into smaller distal area and larger 

 proximal area. Distal area with 2 sensory spots distad of transverse row 

 of about 10 to 18 sensory spots. Lateral regions of smaller distal area 

 each with slightly oblique row of phobae. Larger proximal area with 

 symmetrical subtormae adjoining medially and bearing paired sub- 



