ateral
angles toothed; the disk with a circular striation. Abdomen globose and
pubescent; the scale of the petiole compressed, its superior margin
rounded, and with four minute teeth.

_Hab._ Aru.

10. POLYRHACHIS IRRITABILIS. _P._ niger, pube pallide aurea vestitus;
thorace quadridentato, petioli squamula bidentata.

_Female._ Length 6-1/2 lines. Black, and densely clothed with short pale
golden pubescence; all parts of the insect sprinkled with erect
cinereous hairs; the mandibles shining black, the palpi pale testaceous;
the head elongate, the eyes placed high on the sides of the head,
ferruginous and very prominent. Thorax elongate-ovate; the prothorax
with a short, stout, acute tooth on each side, slightly curved and
directed forwards; the metathorax with a similar tooth on each side
directed backwards; the wings subhyaline, the nervures fuscous; the legs
fusco-ferruginous, the femora and coxae brightest. Abdomen ovate; the
scale incrassate, armed above with two stout acute teeth.

_Hab._ Aru.

This is probably the female of _P. sexspinosus_.

11. POLYRHACHIS LAEVISSIMUS. _P._ niger, laevis nitidusque; metathorace
bispinoso, petioli squamula quadrispinosa, pedibus ferrugineis.

_Worker._ Length 2-3/4 lines. Black, very smooth and shining; the legs
ferruginous, with the coxae, articulations, and the tarsi black. The
thorax not flattened above, or margined at the sides; the division
between the pro- and mesothorax distinct, that between the meso- and
metathorax not discernible, the latter with two erect acute spines; the
scale of the petiole with four short acute spines. Abdomen globose.

_Hab._ Aru.

This species is very like _P. mucronatus_; on close examination,
however, it is seen to be very distinct: it may be at once distinguished
by its larger head, which is wider than the thorax, rounded behind the
eyes, and widely emarginate behind.

12. POLYRHACHIS BELLICOSUS. _P._ capite abdomineque nigris, thorace
femoribusque rufis, thorace quadrispinoso, petioli squamula bihamata.

_Worker_. Length 3-1/2 lines. Black, with the scale of the petiole,
thorax, coxae, and femora blood-red. Thorax: the lateral margins raised
above, with two slightly curved divergent spines in front, and two
stout, acute, long curved spines in the middle, directed backwards; the
scale of the petiole forming a long erect pedestal, which terminates
above in two much bent acute hooks, directed backwards, and being as
high as the bas