Genus Tetramorium Mayr (1855: 423), includes previous Macromischoides, Triglyphothrix and Xiphomyrmex

In Tribe TETRAMORIINI. Synonymy of former genera by (Bolton, 1976, 1980, 1985).

Diagnostic Features - Antennae 11- or 12-segmented, with a 3-segmented club. Antennal scrobes absent to feebly present; frontal carinae often extended as a pair of diverging longitudinal rugae. Mandibles with three or four large teeth apically, followed by a variable number of denticulae. Posterior lateral margins of clypeus raised into a ridge bordering the antennal insertions (see image, right, adapted from Arnold, 1917: 272, and my own photography). Pronotum characteristically square-shouldered in dorsal view due to the sharp anterolateral angles. Promesonotal suture absent; metanotal groove usually impressed. Propodeum with a pair of spines or teeth; metapleural lobes present, acute, and may project as a lower pair of spines. Sting with an apicodorsal lamelliform appendage. Femora usually distinctly swollen.

Mayr (1861: 61) reiterated his earlier (1855) genus description, this is at .

Erect hairs simple in most species, but divided in many former Triglyphothrix, and bizarre in a few species. The former Macromischoides (or at least African members) do not have the posterior lateral margins of the clypeus raised into a ridge bordering the antennal insertions; are less noticeably square-shouldered; and have a more rounded shape to the head in full face view, plus antennal scapes which surpass the occipital margin.

Finzi (1936) provided a key to species from Egypt, this is at .

Speculative Key to Workers from Egypt

1	Frontal carinae long and almost reaching the occiput	2
--	Frontal carinae much shorter, not reaching beyond anterior of eyes	5
2	Whole body covered with quite dense coat of bifid and single hairs (former Triglyphothrix); TL 2.2-3.0 mm; light brown-yellow	lanuginosum
--	Body with only simple erect hairs	3
3	Anterior clypeal margin with a distinct median notch; mandibles striated; sting with lamellate dentiform appendage - Bolton bicarinatum-group	bicarinatum
--	Anterior clypeal margin entire - Bolton simillimum-group - a complex mess in need of detailed revision - see http://antsofafrica.org/ant_species_2012/tetramorium/tetramorium_simillimum/tetramorium_simillimum.htm	4
4	TL 2.0-2.7 mm; frontal carinae full length of face, curving round to make a weak antennal scrobe	simillimum
--	TL 2.1-2.4 mm; frontal carinae near straight reaching about two-thirds point of head, no obvious scrobe; head with weak longitudinal rugulae; yellow-brown to red-brown	caldarium
--	May be synonymous with simillimum	shirlae
.	Frontal carinae short	.
5	Pronotum with distinct anterior dorsal margin; petiole pedicel relatively short, shorter than node in profile; head uniformly longitudinally striate, but may be limited to frons and quite faint; scapes usually failing to reach occiput by about twice their own width	caespitum-group - 6
--	Pronotum with rounded anterior dorsal margin; petiole pedicel longer than node in profile; head with no more than weak striations;	punicum-group - 9
.	caespitum-group	.
6	Generally dark brown and quite strongly sculptured on head and alitrunk	7
--	Variably lighter but with much weaker sculpturation	8
7	TL 2.2-2.6 mm; pedicel nodes smooth on dorsum and laterally spiculate; Iran specimen shown (Bernard, 1967, for France, gave the propodeal teeth as strong and raised)	caespitum - for comparison
--	TL 2.2-2.6 mm; seemingly dark and with alitrunk quite strongly sculptured as in the type caespitum, propodeum with small teeth; funicular segments 3 & 4 more than twice as wide as they are long (Bernard, 1967)	(debilis s.l.) taueret
8	TL 2.5-3.0 mm; finely sculptured, head more finely striate; differing from type (caespitum) by its yellow ochre colour and the smooth pedicel nodes (intermediate between type and punicum)	schmidti
--	TL 2.2-2.6 mm; generally more strongly and evenly sculptured, head and alitrunk longitudinally striate (Bondroit, 1918); pedicel nodes laterally striated and variably so on the postpetiole dorsum (Sanetra et al, 1999)	brevicorne - for comparison
--	TL 2.0-2.5 mm; propodeal spines short; head & alitrunk longitudinally striate but petiole & gaster smooth; yellowish red with gaster darker to red brown (previously misidentified as brevicorne)	semilaeve
.	punicum-group	.
9	TL 3.2 mm; propodeum with spines reduced to tubercles; dark brown (Mohamed et al, 2001)	salwae
--	TL 2.5-3.0 mm; dorsal surface of head (face) distinctly depressed medially; tibiae with stout suberect hairs; sides of head completely straight; petiole node unsculptured and shiny; head and alitrunk with no more than weak sculpturation; propodeal spines short but acute; clear brown, appendages testaceous-yellow	depressiceps
--	TL ca 3 mm; head delicately longitudinally striate; metanotal groove strongly impressed; few erect pale hairs; ferruginous-brown, variably bright	punicum
--	TL 2.0-2.7 mm; head smooth and shiny, more or less flat; brown or darker (often black on the alitrunk)	sahlbergi