THE PONERINE ANTS. 



227 



tion would seem to contradict the statement that the Ponerinse repre- 

 sent the ancestral stirp of the Formicidse, but when we stop to con- 

 sider that we are dealing 1 with a very ancient group, the surviving 

 relicts of a great cosmopolitan and probably Mesozoic fauna, this differ- 

 entiation is what we should expect. The more recent and specialized 

 subfamilies, with the exception of the Myrmicinae, though very rich in 

 species, have not yet been able to develop an equal variety of generic 

 and tribal types, whereas the Poneringe have had 

 time and opportunities to advance and retro- 

 grade along many different lines and to attain a 

 high degree of specialization in certain genera. 

 We may roughly divide the genera of this sub- 

 family into three groups : those which are emi- 

 nently primitive and generalized (Myrmecia}, 

 those which exhibit a mingling of primitive and 

 degenerate traits (Cerapachys, Acanthostichus, 

 Stigmatomma, Amblyopone, Proceratium, Sys- 

 phincta, etc.), and those in which primitive are 

 more or less overlaid by highly specialized char- 

 acters (Odontouiachus, Anochetus, Leptogenys, 

 Prionogcnys, Harpcgnathus, Tlianiiiatoinyrinc.v, 

 Ectatomnia, etc.). 



Although the Ponerinse represent a much larger portion of the ant- 

 fauna in tropical than in temperate regions, they are nowhere a domi- 

 nant group, except in Australia. There these ancient insects occupy 

 a position among ants analogous to that of the monotremes and mar- 

 supials among mammals, and the Rhynchocephalia among reptiles. 

 And it is especially the genus Myrmccia, comprising the "bull-dog 

 ants," which may be said to characterize this fauna and at the same 

 time to represent the prototype of all ants. 



This genus Myrmccia contains a number of species, nearly all of 

 large size (2-2.5 cm.). They are often conspicuously colored, have 

 long, lithe bodies, long legs, well-developed ocelli and large eyes even 

 in the worker phase, and the full number of palpal joints. The struc- 

 ture of 'the base of the abdomen differs from that of other Ponerinse 

 in the powerful constriction between the postpetiole and first gastric 

 segment, so that there is marked off a true postpetiole as in the Myrme- 

 cinae and worker Eciton. Our knowledge of the habits of these 

 remarkable insects is still very imperfect and conflicting for they bite 

 and sting with such ferocity that few observers have cared to study 

 them at close quarters. According to Froggatt (1901) the species of 

 .Myrmccia are largely confined to the Australian littoral, "only one 



FIG. 126. Worker 

 of Sphinctomyrmex 

 taylori of India. (Bing- 

 ham.) 



