bles of a
paler colour; the flagellum fulvous beneath. Thorax: the pubescence
black; wings subhyaline, the nervures dark rufo-fuscous, tegulae
obscurely testaceous. Abdomen with four fasciae of brilliant blue, which
is changeable, with pearly tints in different lights; the posterior
tibiae densely clothed outside with fulvo-ferruginous pubescence; the
pubescence inside is black.

_Hab._ Key Island.

Gen. TRIGONA, _Jurine_.

1. Trigona laeviceps, _Smith, Cat. Hym. Ins., Journ. Proc. Linn. Soc._
ii. p. 51. 8.

_Hab._ Aru; Singapore; India.

Fam. FORMICIDAE.

Gen. FORMICA.

1. Formica virescens, _Fabr. Ent. Syst._ ii. p. 355. 23 [Symbol: male]
[Symbol: female] [Symbol: Mercury].--Lasius virescens, _Fabr. Syst.
Piez._ p. 417. 8.

2. Formica gracilipes, _Smith, Cat. Hym. Ins., Journ. Proc. Linn. Soc._
ii. p. 55. 13 [Symbol: Mercury].

3. FORMICA FRAGILIS. _F._ pallide testacea, elongata et gracilis, capite
postice angustato; thorace medio compresso, pedibus elongatis; squama
incrassata triangulata.

_Worker._ Length 3-1/2 lines. Pale rufo-testaceous, smooth and slightly
shining; antennae elongate, longer than the body, the flagellum slender
and filiform, the scape nearly as long as the head and thorax; head
oblong, narrowed behind the eyes into a kind of neck, the sides parallel
before the eyes, which are black and round, the clypeus slightly
emarginate anteriorly, the mandibles finely serrated on their inner
margin and terminating in a bent acute tooth. Thorax elongate, narrowest
in the middle, the prothorax forming a neck anteriorly; legs elongate
and very slender. Abdomen ovate, the node of the petiole incrassate, and
viewed sideways is triangular or wedge-shaped.

_Hab._ Aru.

This is one of those remarkable forms which recede so greatly from the
normal type of _Formica_ as apparently to indicate a generic
distinction; but in those exotic species of which we have obtained all
the forms, we find many which approach closely to the present insect,
which is probably only the small worker of some already described
species. No one would venture, without the authority of the personal
observation of some competent naturalist, to unite all the forms of any
exotic species of _Formica_.

4. FORMICA FLAVITARSUS. _F._ nigra, elongata et gracilis; thorace
postice compresso, pedibus elongatis, tarsis flavis.

_Worker._ Length 4 lines. Black and subopake; head elongate, narrowed
behind, the clypeus truncate anteri