396 



Anastoechus nitidulus Fabrieius, Malloch, Proc. Biol. Soc. Washington, 



Vol. 29, p. 68. (1916) 

 Toxophora virgata (Men Sacken, Townsend, Psyche, Vol. 6, p. 455. 



(1893) 

 Hyalanthrax hypomelas Maequart, Malloch, Bull. 111. State Lab. Nat. 



Hist., Vol. 11, Art. 4, p. 334. (1915) 

 Hyalanthrax lateralis Say, Malloch, ibid, p. 332. 

 Hyalanthrax alternata Say, Malloch, Proc. Biol. Soc. Washington, Vol. 



29, p. 69. (1916) 



Superfamily TJierevoidea 



The superfamily name of Polytoma was used by Brauer to cover 

 the families Therevidae and Scenopinidae. This grouping is fol- 

 lowed in the present paper, but the name is changed to Therevoidea 

 to conform to the rules governing zoological nomenclature. 



CHARACTERS OF SUPERFAMILY 



Larva. — Head with a cone-shaped anterior protruded portion, 

 which consists of a dorsal sclerite overlapping the sides, and a small 

 ventral sclerite which is not fused to the dorsal one; mandibles well 

 developed; antennae and maxillary palpi distinct; dorsal posterior 

 portion of head consisting of but one rod, the lower rods short or ap- 

 parently absent. Thoracic hairs well developed. Abdominal segments 

 i-6 divided, the entire body appearing to consist of 20 segments ex- 

 clusive of the head; anterior spiracles distinct; lateral abdominal spir- 

 acles absent ; posterior spiracles situated on the antepenultimate seg- 

 ment. 



Pupa. — Head with a pair of antennal thorns, which are directed 

 laterad. Thorax with a long thorn at base of wing, or if this is. ab- 

 sent the abdomen has 2 transverse series of spines on each dorsal seg- 

 ment except basal and apical. 



Imago. — Eyes of males in Therevidae usually contiguous, in 

 Scenopinidae distinctly separated; frons not sunken between eyes; 

 proboscis never elongated. Body with or without wooly hairs; if the 

 abdomen and thorax are somewhat leathery in appearance there are 

 only 3 posterior cells on wing and the third antennal joint has no 

 terminal arista. Legs without hairs or bristles in Scenopinidae, with 

 or without small bristles in Therevidae. 



Family THBRBVIDAB 



FAMILY CHARACTERS 



Larva (PI. LVL Fig. 10). — Very long and slender, tapering 

 towards both extremities ; head small, the posterior internal chitinized 



