46 FOEMICID.-E. 



Genus ODONTOMACHUS. 



Formica, pt., Linn. Syst. Xat. ed. 10, i (1758), p. 582, $ . 

 Odontomachus, Latr. Nouv. Diet. Hist. Nat. xxiv (1804), p. 179. 

 Myrmecia, pt., Fabr. Syst. Piez. 1804, p. 423, . 



Type, 0. hcematodes, Linn., from the tropics of both hemi- 

 spheres. 



2tanf/e. Both hemispheres. 



. Elongate. Head very large and massive iu proportion to 

 the thorax and abdomen, rectangular, longer than broad, in all the 

 Indian species more or less emarginate posteriorly ; mandibles 

 articulated close together in the middle of the anterior margin of 

 the head and not at the lateral angles, long, linear and straight to 

 near the apex, which is abruptly bent inwards at almost a right 

 angle, and terminates in three massive teeth, the innermost one 

 broad and truncate, the apical one unequal, obtusely rounded or 

 subtruncate at apex ; the inuer margius of the shaft of the man- 

 dibles more or less distinctly denticulate ; antennal hollows large, 

 spreading upwards and confluent posteriorly ; antennae 12-jointed, 

 slender, filiform ; eyes comparatively small but prominent, placed 

 laterally on the lower half of the head ; the posterior lateral angles 

 of the head prominent. Thorax much narrower than the head, 

 elongate, rounded above, more or less depressed and emarginate 

 at the meso-metanotal suture ; legs long and slender. Pedicel 

 one-jointed, surmounted by a conical node terminating in a spine 

 above ; abdomen comparatively small, oval, very convex above ; the 

 constriction between the basal two segments not very strongly 

 marked ; the sting exserted. 



$ . Similar, larger ; the mesonotum square, somewhat flat, a 

 deep transverse depression between it and the scutellum, the latter 

 convex, prominent ; the metauotum rounded and arched gradually 

 from base to apex. Wings hyaline, with a brownish tinge ; 

 nervures and stigma brown. 



The species belonging to this genus are eminently forest ants, 

 never, so far as I know, found near human habitations. They 

 nest under stones and fallen trees, aud on being disturbed or 

 alarmed leap about iu a remarkable manner. Notwithstanding 

 their formidable-looking jaws, they seem to be afraid of most 

 other species. I have seen a single of the fierce ^Ecophylla sma- 

 raydina put to flight a whole nest of Odontomachus monticola. The 

 remarkable jumps or leaps taken by ants of this species have been 

 accurately recorded by Mr. Wroughton from a note received from 

 Mr. Ferguson of Travancore. Mr. Ferguson says : " I got some 

 of those (ants) which you said were supposed to jump. I don't think 

 they do, but they can shoot themselves backwards by bending their 

 heads, pressing their mandibles against any firm support, and then 

 bringing them together with a click. I tried them several times, 

 and found that if held by a prelirnb, they always released them- 

 selves in this way, using the imprisoned limb as a fulcrum for 

 the mandibles to" work against." (Jour. Bomb. N. H. Sec. vii. 

 (1892) p. 51.) 



