REVISION OF STKEPSIPTERA PIERCE. 73 



7. Family Dioxocerid^e Pierce. 

 Thorax normal 31. Dioxocera Pierce. 



8. Family Elenchid.e Pierce. 



Mouth parts consisting of mandibles and two-jointed maxillae. 



Species large; first antennal joint elongate, second very short and transverse; 

 frontal process not prominent; oral cavity broad, semicircular. 



36. Deinelenckus Perkins. 

 Species small; first two antennal joints subequal; frontal process prominent; oral 

 cavity triangular; wings having five primary veins from base, with one distal 

 detached vein between the radius and medius, and two brief basal veins rep- 

 resenting the cubitus and first anal 32. Elenchus Curtis. 



Mouth parts consisting of mandibles and two-jointed maxillse, bearing on the first 

 joint an elongate, knobbed, linear, chitinous filament; species small; oral cavity 

 triangular; wings as in the preceding, but without traces at base of cubitus and 

 first anal 34. Mecynocera Pierce. 



(37. Colatina West wood. 

 33. Elenchoides, new genus. 

 35. Pentagrammaphila, new genus. 



Artificial hey to genera based on wing venation. 



1. Eight primary veins from base (costa, subcosta, radius, medius, cubitus, three anal). 

 (The costa is always a very short, inconspicuous vein at the base and is merged 



with the subcosta). 



a. One distal detached vein between the subcosta and radius; first and second 

 anal veins apically united Mengea Grote. 



b. Two detached branches of radius and two of medius between radius and 

 medius Apractelytra Pierce. 



IXenos Rossi. 

 Pseudoxenos Saunders. 

 Paraxenos Saunders. 

 Stylops Kirby. 



d. One detached branch of radius and one of medius between radius and medius; 

 and detached branch of medius between medius and cubitus. Eupathocera Pierce. 



e. Medius curved upward and branched toward apex Myrmecolax Westwood. 



2. Seven primary veins from base. 



a. Cubitus appearing as a detached vein; radius and medius basally united; with 

 a detached branch of each between them Hylechthrus Saunders. 



b. Third anal lacking. 



A detached branch of radius and one of medius between radius and medius; 



a detached branch of medius between medius and cubitus. 



phthalmochlus Pierce. 

 Radius sometimes broken for a short distance; a detached branch of medius 



between radius and medius; a detached branch of medius immediately 



behind medius fAcroschismus Pierce. 



ySchistosiphon Pierce. 

 Radius broken for a considerable distance; medius with one detached and two 



connected branches in front of it Trioxoccra Pierce. 



e. Cubitus lacking. 

 ■ Two detached branches of medius between radius and medius. 



Medius branched near apex behind Pentoxocera Pierce. 



Medius with detached vein commencing just before the apex on its 



anal side Halictophagus Dale. 



Two detached branches of medius between radius and medius. 



Pentacladocera Pierce. 



