24 
Psyche 
[March 
ence of cephalic striations or rugulae. Also, two minute 
denticles between the apical and the penultimate teeth 
constitute a further similarity. The lack of a furrow in 
harhowri and mjoebergi, as well as the nature of the head 
sculpture and the mandibular characters in these species, 
at once separate them from the new species. The forms 
with a frontal furrow, namely, hinghami, donisthorpei, 
tvilliamsi and bakeri, may all be distinguished from karnyi 
in various ways. In bakeri the dorsum of the head is en- 
tirely smooth, while in tvilliamsi it is entirely coriaceous 
or covered with a sculpture of minute and contiguous 
punctures, giving the surface a matte appearance. The 
frons and clypeus of donisthorpei and binghami, according 
to Creighton, are reticulo-striate, but in the latter species 
the striae are feebler and rather fragmented. The head of 
karnyi possesses striations also, but these are less wavy, 
being curved only where they pass around the antennal 
insertions, and furthermore, they are confined to the frons. 
In addition, karnyi differs from binghami in that the man- 
dibles each bear ten teeth (rather than nine), apart from 
the minute denticles between the two terminal teeth. The 
two basal teeth are themselves mere denticles, but never- 
theless distinct, and all teeth show a gradual increase in 
size outward toward the apex of the mandible. The 
clypeus presents lateral furrows or depressions separating 
an elevated median portion from the marginal flanges, 
and such a condition seems to be lacking from binghami. 
The thorax of karnyi also contrasts noticeably with that of 
binghami, for the pronotum in profile is higher and more 
convex, and the mesonotum is decidedly saddle-shaped 
and narrowed, recalling the condition in williamsi, with 
strong longitudinal rugae traversing it. The mesonotal 
spiracles are sizable openings and are raised on prominent 
tubercles. The epinotum is as high as the pronotum, very 
convex resembling in general appearance the same struc- 
ture in Myrmecocystus , and the angle between the basal 
and declivious faces is only weakly indicated. The petiole 
has short anterior and posterior peduncles, with a high, 
vertical scale, the front and rear surfaces of which slope 
slightly. The petiolar crest is flat but is inclined a little 
posteriorly and ventrally. 
