3.)

_Hab._ Aru; India; Philippine Islands.

3. POLYRHACHIS MARGINATUS. _P._ niger; antennis, palpis pedibusque
ferrugineis; thoracis marginibus recurvis, metathorace petiolique
squamula bidentatis.

_Worker._ Length 2-1/2 lines. Black; the antennae and legs ferruginous;
the head and thorax rugose; the prothorax transverse, its anterior
margin slightly curved, with the lateral angles produced forwards and
very acute; the thorax narrowed to the metathorax, which is armed with
two divergent acute spines. Abdomen velvety black and globose; the scale
of the petiole produced laterally into long, bent, acute spines, which
curve backwards to the shape of the abdomen.

_Hab._ Aru.

4. POLYRHACHIS HOSTILIS. _P._ niger, longitudinaliter striatus, thoracis
marginibus expansis, metathorace squamulaque petioli spinis duabus
crassis acutis curvatis.

_Worker._ Length 3 lines. Black; the head and thorax longitudinally
striated, the abdomen very finely and evenly so; the prothorax
transverse, wider than the head, the anterior and lateral margins
recurved, the latter acute at their anterior angles, and rounded at the
posterior ones; the lateral margins of the mesothorax recurved, a deep
notch between the meso- and metathorax; the latter with a long, stout,
curved, acute spine on each side. The scale of the petiole produced
above on each side, into a long, curved, stout, acute spine, which
curves backwards round the sides of the abdomen.

_Hab._ Aru.

5. POLYRHACHIS LONGIPES. _P._ niger; flagelli dimidio apicali tibiisque
anticis pallide ferrugineis, prothorace petiolique squamula bidentatis.

_Worker._ Length 3 lines. Black; the head and thorax finely rugose; the
antennae elongate, longer than the insect; the apical half of the
flagellum pale ferruginous. Thorax rounded above, the sides not
margined; two spines on the thorax anteriorly, two on the metathorax,
and two on the scale of the petiole; the legs elongate, with the
anterior tibiae ferruginous. Abdomen globose, sometimes rufo-fuscous, or
the base obscurely rufous.

_Hab._ Aru.

6. POLYRHACHIS SERRATUS. _P._ niger; capite thoraceque rugosis, abdomine
dense punctato, squama petioli transversa, margine superno serrata.

_Worker._ Length 2 lines. Black, with the antennae and legs ferruginous.
Thorax oblong-quadrate or very slightly narrowed towards the metathorax,
slightly convex above, not margined at the sides, the divisions not
perceptible; the head and thorax rugo