1951] 
Creighton — Arizona Ants 
55 
cable characteristic which will define the members of this 
ill-conceived and conglomerate subgenus. 
The situation in the subgenus Manniella is simpler, but 
this is mainly because it contains a much smaller number 
of species than Myrmaphaenus. For this subgenus is also 
cursed with heterogeneity. When Manniella was first set up 
by Wheeler in 1921 it contained only the Cuban species 
sphaericus and its subspecies sphaeralis. This species had 
previously been assigned to Colobopsis by some workers 
and to the subgenus Myrmeurynota by others. Wheeler’s 
move was a sound one, for it recognized the peculiar struc- 
tural features which mark the major worker of this species. 
The major worker of sphaericus possesses ulcerate cheeks 
and peculiarly modified frontal lobes. Each frontal lobe 
is large, laterally expanded and with its anterior half dis- 
tinctly concave. The two concavities are separated by a 
prominent median septum where the lobes join. While this 
configuration of the frontal lobes may be nothing more than 
the specific characteristic of sphaericus it seems to have no 
close counterpart in any other species in the genus Campo- 
notus. Hence the subgenus Manniella can if necessary, be 
based upon the unique structure of the frontal lobes of 
sphaericus as long as the subgenus is limited to that species. 
With this auspicious start it is most unfortunate that Emery 
and Wheeler should have subsequently added to Manniella 
species which do not agree in the characteristics just men- 
tioned. In 1925 Emery transferred ulcerosus to Manniella 
and in 1934 Wheeler placed linnaei and championi in this 
subgenus (5). Each of the species transferred to Manniella 
has a major worker with ulcerate cheeks but none of them 
has frontal lobes comparable to those of sphaericus. Emery 
was clearly aware of this discrepancy, for he commented 
on it when he transferred ulcerosus to Manniella. No doubt 
Wheeler was also, but by 1934 the structure of the frontal 
lobes had been subordinated to the presence of ulcers on 
the cheeks as the definitive characteristic of the subgenus 
Manniella. It is instructive to note that both Emery and 
Wheeler tried to bolster this character with others which 
would give a better definition to Manniella. Thus Emery 
postulated that the worker caste in Manniella is strictly 
