214 
Psyche 
[June 
Iridomyrmex goepperti 
Hypoclinea gopperti Mayr, 1868, Beitr. Naturk. Preuss. 1: 56, pi. 1, fig. 3-7; pi. 3, 
fig. 42-46, worker, queen, male. 
Iridomyrmex goepperti: Wheeler, 1914, Schrift. Phys-okon. Ges. Koenigsberg, 
55: 90-91, worker. 
Ctenobethylus succinalis Brues, 1939, Ann. Entomol. Soc. Amer. 32: 261-263, 
fig. 7, 9 (recte worker). Type: Museum of Comparative Zoology, Harvard 
University, No. 7666. New synonym. 
Brues’ figure errs in omitting the spurs, present one on each 
tibial apex, and also in showing the trunk as without an impressed 
metanotal groove; actually, this groove is distinctly though mod- 
estly impressed in the type. 
/. goepperti is left in Iridomyrmex for the time being, although 
this genus is almost surely a diphyletic assemblage. The Indo- 
Australian species, including the type species of Iridomyrmex, 
/. purpureus (=/. detectus ), differ from the New World members 
(/. humilis group) in that they lack Pavan’s apparatus (with gland) 
at gastric sternites IV and V. The status of the Baltic Amber 
Iridomyrmex with respect to this character has not been deter- 
mined, because the few samples available to me have the under- 
side of the gastric apex obscured by films. As already stressed 
by Wheeler, I. goepperti lacks a distinct epistomal (frontoclypeal) 
suture and frontal triangle, conditions atypical for Iridomyrmex 
(and for ants in general). It is likely also that the living species 
of Iridomyrmex divide further into groups on the basis of pro- 
ventricular anatomy, position of compound eyes, larval mor- 
phology, karyotype, and perhaps other characters. If some of 
these groups represent different genera, as seems likely, we do 
not know yet how the divisions will cut, or what genus-level names 
are available. 
The “ Iridomyrmex Problem” is an exceptionally complex one, 
calling for nothing less than a full-scale revision of the Tapinomini. 
Until that revision can be made, the genus Iridomyrmex is best 
left as it stands, and Ctenobethylus, with type and sole species 
C. succinalis, is its new synonym. 
In recent correspondence with E. O. Wilson and H. E. Evans, 
I learned that they had jointly examined Ctenobethylus succinalis 
several years ago, and tentatively considered it to belong to 
Iridomyrmex, but they did not complete the study. I am grateful 
