90 William Morton Wheeler. 



7650/364, 7699/413, and 979/583 and, in the same collection, two 

 specimens (7517/231 and 9649/558), which, he doubtfully referred to 

 this species. 



Iridomyrmex gosppe^'ti Mayr. 



Hypoclinea gopperti Mayr, Beitr. Naturk. Preuss. I, 1868, p. 56, Taf. I, Figs. 3—7, 



' Taf. Ill, Figs. 42-46, $ 9 cf- 

 Bothriomyrmex goppertii Dalla Torre, Catalog. Hymen. VII, 1893, p. 170; Ern. 

 Ais^DRE, Bull. Soc. Zool. France, XX, 1895, p. 82; Haxdlirsch, Foss. 

 Insekt. 1908, p. 871. 



I was at first inclined to adopt the view of Dalla Torre and 

 subsequent writers that this ant is a true Bothriomyrmex, but a closer 

 study convinces me that it is more probably an Iridomyrmex. The 

 thorax of the worker, to be sare, is much like that of Bothriomyrmex 

 in having a rather feeble constriction in the mesoepinotal region, but 

 this is also the case in certain species of Iridomyrmex, notably in the 

 North American I. analis Ern. Andre. The head of the amber species 

 is certainly not like that of any existing species of Bothriomyrmex 

 known to me, but narrowed anteriorly, with slightly concave cheeks 

 and its posterior portion is broad and subcordate as in most species 

 of Iridomyrmex. Moreover, the maxillary palpi are 6-jointed, the labial 

 palpi 4 -jointed, and there is considerable variation in stature just as 

 there is in some recent species of Iridomyrmex. This latter character 

 and also certain peculiarities of the head, especially of the clypeus, 

 with its straight anterior border and the inflated, slightly projecting 

 sides, especially in large specimens, together with the obsolescence of 

 the sutures between the clypeus and head and the absence of a distinct 

 frontal area and frontal groove, recall the conditions in the genus 

 Liometopum. Mayr gives the length of the worker as 3,4 — 6 mm. 

 I regard the later measurement as excessive and as probably referring 

 to other species of Iridomyrmex, probably I. samlandicus, which may 

 have been confounded with the species under discussion. It is not 

 improbable, however, that I. goepperti represents an ancestral and 

 generalized form from which both Bothriomyrmex and Liometopum have 

 been derived, the former by a reduction of the number of palpal 

 joints, the latter by an increase in the stature variability of the 

 worker and of the pilosity and pubescence of the body. 



As Mayr has adequately figured and described all three phases 

 of I. goepperti I will here omit a detailed description. It is far and 

 away the most abundant and dominant ant in the amber fauna. 

 Mayr examined 580 specimens, Ern. Andre 309. I have seen 4539 

 specimens which are distributed as follows: 3686 workers and 2 fe- 



