1985] 
Wilson — Cretaceous and Eocene amber ants 
215 
amber piece along a new plane in order to see the opening of the 
acidopore, I shattered and lost the rear part of the abdomen before 
this opening came into view. Hence I cannot be certain that the ant 
possessed a typically circular formicine acidopore. Additionally, the 
absence of a circlet of hairs at the tip of the abdomen and paired 
bristles on the alitrunk, on which the generic diagnosis rests, could be 
the result of postmortem deterioration. However, I doubt that such 
is the case, because the body form as a whole and the entire dorsal 
cuticular surface were preserved in excellent shape, without the kind 
of distortion and rupturing usually accompanying severe decay in 
amber specimens. Also, at least two well-preserved hairs were pres- 
ent on the ventral surface of the gaster, as depicted in Fig. 6. 
To ascertain the status of Protrechina I surveyed representatives 
of all of the living genera of Formicinae with reference to the two 
characters in pilosity. In only two genera, Oecophylla and Campo- 
notus (and only in a few species of the latter), is the circlet of 
acidopore hairs lacking. Conversely, only some of the species of 
Acantholepis and Brachymyrmex share the Paratrechina trait of 
coarse paired setae on the alitrunk dorsum. Thus Protrechina is not 
unique among the Formicinae in its possession of the two character 
states that distinguish it from Paratrechina. 
Protrechina carpenteri, if I have interpreted its morphological 
features correctly, is the first member of the Formicinae recorded 
from a definitely dated Eocene deposit. 
Summary 
(1) The first ants from the Canadian amber are described as 
Sphecomyrma canadensis, providing a record of the primitive Cre- 
taceous subfamily Sphecomyrminae geographically intermediate 
between the New Jersey and Siberian collections recorded earlier. 
(2) The first specimens of Eocene ants definitely assignable to 
higher subfamilies have been discovered in amber from Malvern, 
Arkansas: Eocenidris crassa (Myrmicinae), Iridomyrmex mapesi 
(Dolichoderinae), and Protrechina carpenteri (Formicinae). 
Acknowledgements 
I am grateful to Barry Bolton, William L. Brown, Jr., and Frank 
M. Carpenter for invaluable advice and assistance given during this 
study, to James F. McAlpine for supplying the Canadian amber 
