56 W. A. SANDS 



4 Fontanelle subject to pronounced sexual dimorphism: in $, large sunken pale area 



approximately equal in size to compound eye; in q" small black slit or obsolete, 

 surrounded by dark pigmented area larger than ocellus . . . acholus (p. 139) 



- Fontanelle not so ........... . 5 



5 Left mandible with apical tooth shorter in proportion to distances between marginal 



teeth, complex ratio La/Li. L m , under 6-5 (known range 4-5-5-5) ... 6 



- Left mandible with apical tooth proportionately longer, La/Li. L m , over 6-5 (known 



range 7-5-13-2) ... 7 



6 Meso- and metanota proportionately wider at constriction, M/W, 0-33-0-36. Left 



mandible with proximal end of subsidiary marginal tooth separated from molar 

 prominence by wide notch; postclypeus more strongly inflated, Pcl/W, 0-26-0-27, 

 with distinct median suture ...... irrixosus (p. 100) 



- Meso- and metanota narrower at constriction, M/W, 0-22-0-28. Left mandible 



with subsidiary marginal tooth only just clear of molar prominence, and with 

 markedly concave cutting edge; postclypeus weakly inflated Pcl/W, 0-22-0-24, 

 median suture indistinct or absent ..... etnpodius (p. 94) 



7 Ocelli almost touching compound eyes, separated by one-quarter or less of own 



least diameter ........ . obstructus (p. 88) 



- Ocelli separated from compound eyes by at least one-third own least diameter . 8 



8 Ocelli small and separated from eyes by more than own least diameter aganus (p. 69) 



- Ocelli larger, separated from eyes by less than own least diameter ... 9 



9 Larger, W, 0-98-1-01; meso- and metanota wider at constriction M, 0-29-0-33, N, 



0-29-0-33, Li/M.N, 1-40-1-81 ......... 10 



- Smaller, W, 0-69-0-94; meso- and metanota narrower at constriction, M, 0-14-0-25, 



N, 0-14-0-28, Li/M.N, 1-99-5-35 ......... 11 



10 Postclypeus more inflated, apical teeth of mandibles shorter, Pc1/Ra, 3-00-3-22, 



L A /Li, 0-52-0-56 ......... hapalus (p. 72) 



- Postclypeus less inflated, apical teeth of mandibles longer, Pc1/Ra, 2-61, La/Li, o-66 



mitts (p. 77) 



11 Postclypeus less inflated, apical teeth of mandibles longer, Pc1/Ra, 1-93-2-00, 



Fya/Pm, 1-04-1-05 ......... amicus (p. 58) 



- Postclypeus more inflated, apical teeth of mandibles shorter, Pc1/Ra, 2-83-4-15, 



Ra/Ri, 0-65-0-89 ........... 12 



12 Right mandible with second marginal tooth distinctly broader based and more 



robust than first, distal margin slightly convex (Text-fig. 74) . comis (p. 63) 



- Right mandible with marginal teeth approximately equal or first more prominent, 



distal margin of second straight or slightly concave . . . . . 13 



13 Fore tibia with third (outer) apical spur, vestigial. Smaller, W, 0-69-0-73 benignus (p. 61) 



- Fore tibia with third apical spur only slightly smaller than other two. Larger, W, 



073-0-94 .... 14 



14 Meso- and metanota proportionately wider at constriction, apical teeth of mandibles 



slightly shorter, M/Ra, 3-40-3-77, Li/M.N, 1-99-2-32. Larger, W, 0-86-0-94. 

 Compound eyes prominent in proportion to own diameter (Text-fig. 204) 



impedians (p. 98) 



- Meso- and metanota narrower at constriction, apical teeth slightly longer, M/Ra, 



2-10-3-00, Li/M.N, 2-69-4-13. Smaller, W, 0-73-0-86, compoundeyes not prominent 



in proportion to own diameter . . . . . . . . .15 



15 Posterior margin of head capsule evenly rounded. Smaller, W, 0-73-0-75. Left 



mandible, apical tooth longer, La/Li, 0-69-0-79, proximal end of subsidiary 

 marginal tooth separated from molar prominence by definite notch (Text-fig. 75) 



eumenus (p. 67) 



- Posterior margin of head slightly unevenly rounded. Larger, W, 0-75-0-86. Left 



mandible, apical tooth shorter, La/Li, 0-52-0-64, proximal end of subsidiary 

 marginal tooth just clear of molar prominence (Text-fig. 73) . concilians (p. 65) 



