350 FORMICID,!:. 



i"'. Head and abdoujen black 

 or dark cawtaneous red ; 

 thorax yellow, wholly or 

 ill part, 

 a'. Medial lobe of clypeus 

 long rectangular ; the 

 lateral angles acute. 

 a'*. Head much broader pos- 

 teriori}'^ than in front. . C. dlchrous, p. 806. 

 b^. Head only as broad pos- 

 teriorly as ill front . . C. basalts, p. 352. 

 b'. Medial lobe of clypeus 

 short, not much pro- 

 duced ; the lateral 



angles rounded C irntans, p. o.>3. 



i'. Tibife without spines be- 

 neath, 

 «®. Head, thorax and abdomen 

 finely rugulose opaque. 

 a'. Castaneous brown .... C. baclius, p. 358. 

 b"'. IJeddish yellow, apex of 



abdomen darker C. nicobarensis, p. o6-4. 



i". Head, thorax and abdo- 

 men sparsely punctured, 

 shining, not opaque. 

 a'. Head, thorax and abdo- 

 men dark castaneous 

 brown. 

 w'*. Pronotum longer than 

 mesonotum, strongly 

 constricted, antei'iorly 



forming a neck C. cari/i, p. 365. 



b'^. Pronotum about equal 

 in length to meso- 

 notum, only slightly 

 constricted, in front 

 not forming a distinct 



neck C. thraso, p. 350. 



b~. Head and abdomen fus- 

 cous brown or black (in 

 ^ min. head sometimes 

 yellow) ; thorax honey- 

 yellow. 

 ««, Distance between the 

 antennal carinas equal 

 to distance between 

 eyes and antennal 



carinae C. mitls, p. 355. 



h^. Distance between an- 

 tennal carince dis- 

 tinctly greater than 

 between eyes and 

 antennal carinas .... C. paflidus. p. 357. 

 B. Regular arch of the thorax interrupted by 

 the apex of the metanotum being truncate. 

 a. Mandibles toothed at apex and also on 



inner margin C. t/i'i/as, p. 369. 



