194 CHARLES A. BLAKE. 



Genus 2, MrTIL,L.A Linu. 



Male. — Head usually transvei'se and compressed, eyes moderately 

 large, ovate, more or less emarginate, but in a few species they are 

 entire. The ocelli placed in a triangle on the vertex. The antennse 

 subfiliform, gradually tapering to the apex, which is acuminate, in- 

 serted on the sides of the base of the cly]3eus. The mandibles ar- 

 cuate and tridentate, but varying occasionally in this respect. The 

 prothorax extending laterally to the origin of the wings ; the tegulae 

 usually very large. The anterior Avings with one marginal and three 

 submarginal cells, the marginal usually of a semi-circular form ; the 

 three submarginal cells subequal, the second and third each receiving 

 a recurrent nervure, the second nervure being almost obsolete, as 

 well as the third transverso-cubital nervure, from the middle of which 

 emanates a more or less abbreviated nervure, never extending to the 

 apex of the wing ; in a few exotic species the third submarginal cell 

 is obsolete. The legs moderately long and pubescent. Abdomen 

 ovate, the first segment subpyriform or sometimes }>etiolate, the second 

 campanulate, and the apex curved. 



Female. — Head suborbiculate, or subquadrate, sometimes enor- 

 mously developed and armed beneath with two or more formidable 

 spines ; the ocelli always wanting, the eyes ovate, entire ; mandibles 

 arcuate and usually unidentate. Thorax longitudinal and truncate 

 interiorly and posteriorly ; in some exotic species much narrowed 

 behind. Legs more robust than in the male and armed exteriorly 

 with spines. Abdomen similar to the male. 



The species, which are not numerous, may be divided into three 

 divisions, viz. : 



DIVISION I. 



Neuration of anterior wing as represented by figure 3 ; the first 

 abdominal segment small, but gradually dilated to apex, where it is 

 sessile with the base of second segment, as in figures 4 and 5. 



Fis?. 3. Fig. 4. Fig. 5. 



