82 
Psyche 
[•June 
shape, widest in the middle of the first segment, and taper- 
ing to a pointed posterior end. Entire body notably elon- 
gated and depressed. 
All surfaces glabrous, very smooth and shining, the only 
indication of sculpture being the minute pits from which 
the hairs arise and a slight shagreening of the gaster. Hairs 
delicate, pointed, pale yellow, and present on the head, tho- 
rax, petiole, gaster, scapes, funiculi, and all segments of 
the legs. Pubescence very sparse but present on most sur- 
faces; slightly denser on the gaster and thickest on the 
funiculi. 
Forewing 5.4 mm. long, with one cubital cell and no closed 
discal cells ; brownish in color. 
Color of body black throughout, except tarsi, articulations 
of legs and antennae, and the mandibles which are dark 
reddish brown. 
Holotype: winged female (M.C.Z. No. 28555). 
Described from a single specimen collected by Dr. 
Kenneth Cooper at Turrialba, Costa Rica. Attached to it is 
the number Cr 49 F 13. 
In 1903 Emery described Camponotus mirabilis, and later 
(1911), described two new species, C. sphenocephalus , and 
C. longipilis, with its variety C. 1. postangulata, belonging 
to the same group. To-date these seem to be the only forms 
known, and are all from Peru. Emery placed these ants 
in the subgenus Myrmostenus in 1920, and they are so listed 
in the Genera Insectorum (1925, Fasc. 183, p. 161). They 
have in common a very large size, 16 mm. or more, with very 
straight and elongated bodies and for the most part shining 
surfaces, giving them a striking appearance. The new 
species differs from all these in its much smaller size and its 
color which is practically solid, shining black. Despite this, 
it appears to belong in the subgenus and to represent a di- 
minutive type. As all forms of Myrmostenus are known 
only as females, it has been suggested that the workers when 
found will show them to be members of some other group 
of Camponotus , and although this was mentioned by Emery, 
it has so far not been demonstrated ; consequently, the con- 
clusion that these ants form the subgenus Myrmostenus , 
for the present must rest. The new ant from Costa Rica is 
