INSECUTOR INSCITI.^ M^NSTRUUS 113 



Upright forked black scales ; ocular margins and cheeks clothed 

 with broad white scales. Mesonotum dark brown, clothed with 

 rather coarse, narrow curved, shining yellowish brown scales, 

 much paler ones along margins and about antescutellar bare 

 space ; bristles rather sparse, long and black. Scutellum clothed 

 with fine pale scales ; median lobe with six or seven long brown 

 bristles, the lateral lobes with four bristles. Postnotum luteous 

 brown. Pleurae pale brownish luteous, with patches of broad 

 white scales. Abdomen depressed, blunt at tip ; dorsal vesti- 

 ture of dull black scales, each segment with a broad, creamy 

 white basal band becoming narrower toward the sides ; large 

 triangular white patches laterally at bases of segments, not 

 visible from above ; venter entirely soiled white scaled. Wings 

 hyaline, moderately broad ; fork of second vein nearly twice 

 as long as its stem ; scales along the veins blackish, the out- 

 standing ones linear; third and fifth veins with dense, rather 

 broad, truncate appressed scales which give these veins a dis- 

 tinctly blacker appearance. Halteres pale, with blackened 

 knobs. Legs rather long and slender, black scaled, the tarsi 

 unhanded ; front femora with a broad white line along the 

 whole length on outer side. Claws simple. Length : Body 

 about 3 mm., wing 3.3 mm., 



Male. Proboscis straight, slightly enlarged toward apex, 

 black scaled. Palpi exceeding the proboscis by nearly the 

 length of the last joint, black scaled ; end of long joint and 

 last two joints slightly thickened and bearing many rather long 

 black hairs; last two joints subequal and with some pale scales 

 at base. Antennae loosely plumose, the shortened joints slender 

 and longer than usual ; hairs of whorls blackish. Abdomen 

 long, depressed, rather narrow, slightly broadened beyond 

 middle ; dorsal white bands broad, transverse, occupying nearly 

 the basal halves of the segments. Wings narrower than in 

 the female ; second vein with the fork and stalk subequal in 

 length. Claws unequal; formula: 1.1-1.1-0.0. Length: Body 

 about 3.5 mm., wing 3 mm. 



Type: Cat. No. 19978, U. S. Nat. Mus. 



The larvae occurred rarely in rock pools associated with the 



