66 Psyche [March-June 
by certain constant characters as indicated above. The queens, 
moreover, show decided differences, and it is felt the specimens 
represent a new form which deserves specific rank. While 
minimum is widely distributed from east to west, there seems to 
be little cause for questioning the distinctness of the form I have 
called peninsulatum after the portion of the country from which 
it was obtained. In all probability it will be found on some of 
the adjacent islands; it may even be a West Indian ant which 
has entered continental United States at its most southern ex- 
tremity. If this remains an undoubted species, the known 
formicid fauna of Florida will have increased to 118 ants. Dr. 
M. R. Smith (1944), in an addition to the list of ants of that 
state, brought the total from 107 to 117 species. 
The new ant appears to be very similar to one described by 
W. L. Brown as Monomorium viridum from New Jersey. Judg- 
ing from the description of this species, the female M. peninsu- 
latum may be said to differ from that of viridum in the follow- 
ing respects. There are no transverse striae in the ocellar tri- 
angle nor behind it, the anterior faces of the petiole and post- 
petiole are sculptured and not smooth, the clypeal teeth are 
quite short and blunt, the head and thorax have slight or no 
indication of metallic blue, and the color of the abdomen is 
metallic blue, not green. The size is a little smaller than viri- 
dum , the female measuring 4.5 to 5.0 mm. instead of 5.3 to 5.7 
mm., and the worker being 1.8 to 2.0 mm. instead of 1.8 to 
2.8 mm. 
Monomorium minimum subsp. emersoni subsp. nov. 
Worker. — Length 1.6-1. 8 mm. 
Practically indistinguishable from the same caste of M. mini- 
mum (typical) except that it is perhaps a shade lighter in color. 
Female. — Length 4.3 mm. 
Differs from the queen of minimum in the much more slender 
construction of the head and thorax, being much narrower than 
in the typical form; abdomen, however, of the same width. The 
petiole and postpetiole are both slightly wider than in minimum , 
and the petiolar node is more rounded and with a more concave 
anterior face which causes the peduncle to contrast with the 
node; sides finely rugose. The thorax bears wings, as shown by 
their stumps, but none were present on the specimens examined. 
