.

_Hab._ Aru.

3. MYRMICA THORACICA. _M._ capite abdomineque nigris; antennis,
mandibulis thorace pedibusque flavis.

_Worker._ Length 3/4 line. Head and abdomen jet-black; the antennae,
thorax, and legs of a clear honey-yellow; the mandibles of a more
obscure yellow; the anterior margin of the thorax transverse, the
lateral angles acute, narrowed from thence to the base of the
mesothorax, the disk anteriorly slightly convex; the metathorax armed
with two acute spines. Abdomen nearly round, and very smooth and
shining; the first node of the petiole vertical anteriorly, and
gradually rounded behind, the second node transverse, its anterior
margin straight, the angles rounded, the sides narrowed towards the
abdomen; the club of the antennae 3-jointed.

_Hab._ Aru.

The singular form of the thorax of this species, as well as the
construction of the nodes of the petiole, appear to indicate an
uncharacterized division of the genus _Myrmica_.

4. MYRMICA SUSPICIOSA. _M._ rufo-testacea, laevis, tota nitidissima nuda;
mandibulis, antennis, pedum articulationibus tarsisque palles-centibus;
metathoracis spinis minutissimis.

_Worker._ Length 1 line. Rufo-testaceous and very smooth and shining;
the antennae as long as the insect; the flagellum, mandibles, tarsi, and
articulations of the legs pale testaceous. The thorax narrowed
anteriorly into a short neck, behind which it is dilated, the sides
being rounded, the meso- and metathorax narrower and of nearly equal
width, the spines of the metathorax minute and slender. The first node
of the petiole somewhat wedge-shaped, the second globose, the abdomen
very smooth and shining; club of the antennae 3-jointed.

_Hab._ Aru.

I can detect no specific difference between this and _Myrmica laevigata_,
taken by myself in the neighbourhood of London; but it is not uncommonly
met with in hothouses, near to which I captured my specimen. I believe
_M. laevigata_ is identical with _OEcophthora pusilla_, the House-Ant of
Madeira.

5. MYRMICA MELLEA. _M._ capite thoraceque flavis; abdomine pallide
fusco.

_Worker._ Length 1-3/4 line. Head, antennae, thorax, and legs
honey-yellow and very smooth and shining; thorax strangulated at the
base of the metathorax, which is not spined; the first node of the
abdomen is oblique anteriorly, and vertical behind, the second node
subglobose. Abdomen: the base honey-yellow, the apical margin of the
first segment, and the following segments entir