1951] 
Creighton — Arizona Ants 
57 
done so at present because of the possibility that ulcerosus 
may fit into one of the subgenera which Emery fused to 
make Myrmaphaenus. Since it is clear that Myrmaphaenus 
will have to be drastically revised if its constituent species 
are to be put on a sound taxonomic basis, any piecemeal 
attempt in this direction would be premature. One may 
earnestly hope that the next revisionary effort applied to 
Myrmaphaenus will be thorough enough to give us a work- 
able version of this highly unsatisfactory group. In the 
meantime the plan which causes the least disarrangement is 
to transfer to Myrmaphaenus the species ulcerosus , linnaei 
and championi and to restrict the subgenus Manniella to 
sphaericus and its subspecies sphaeralis. I propose to fol- 
low this plan and trust that other myrmecologists will see 
the matter in the same light. 
I wish to present here certain descriptive details to aug- 
ment the figures of ulcerosus included in this paper. These 
will be restricted to the minor and media workers and the 
female. Both the ulcerate and the non-ulcerate phases of 
the major worker of this insect have been described else- 
where and need no further description here. 
Worker minor: head (exclusive of the mandibles) 1.25 
mm. long; thorax and petiole 2 mm. long; total length 5.5- 
6.5 mm. Erect hairs long, thin, white and usually with 
sharp tips; abundant on the rear of the head, the entire 
thorax and the abdomen. Hairs on the mandibles, clypeus, 
cheeks and gula for the most part notably shorter than 
those on the rear of the head. Femora with short erect 
hairs on their lateral and flexor surfaces. Those on the 
extensor surface mostly appressed and often largely lim- 
ited to the outer half of the femur. Tibiae with abundant 
erect hairs. Those of the tarsi and antennal funiculi finer, 
shorter and semierect. Antennal scapes covered with very 
fine, appressed, yellow pubescence and with a few short, 
yellow, semierect hairs usually present on the outer half 
of each segment. Head and thorax finely and densely granu- 
lose (under high magnification this granulation may be seen 
to consist of close-packed, circular craters) . Coxae and peti- 
ole with a delicate, even, reticulate sculpture. Gaster finely 
shagreened, somewhat more shining than the coxae and the 
