The Hellenistic armies of the Eastern Mediterranean all fielded armies modelled closely of those of Phillip and Alexander. The armies were composed of proffesional soldiers rectruited from a small portion of citizens. Carthage had a very small citizen body and early on abandoned this practice of relying on their own citizens for the bulk of their armies, being unwilling to risk heavy casaulties amongst it's own population. Only when the city was under direct threat was the citizens obliged to undergo military service. On the field they formed up as close order infantrymen fighting in phalanx, and armed with shields and long spears. Often though their effectivness was poor, often as a result of inexperience.

Since Carthage lacked citizen manpower of their own their armies mostly rectruited foreign soldiers. Lybians provided the steadiest and most disiplined element in the armies. Their close formation infantry were equipped with long spears and oval or round shields, and wore helmets and most likely linen cuirasses. Libyan cavalry were also close order troops armed with thrusting spears trained to deliver a controlled, shock charge. They may have also provided some skirmishers. Each soldier armed with a bunch of javelins and a small shield.

The Numidians were renowned for their superb light cavalry, who rode their small horses without either briddle or saddle and harrased the enemy with volleys of javelins. They avoided close combat unless conditions were absolutely in their favour. Numidian armies also consisted of infantry skirmishers equipped with javelins and the same round shield as the cavalry and it is possible that contigents of these troops were also sent to the Carthaginian army.

From Spain the Punic army got both light and heavy infantry, who's normal dress was a white dress with purple outlines. The heavy infantry fought as a dense phalanx, carried a long body shield, armed with a heavy throwing spear, and a sword; either the short thrusting weapon which provided the model for the Gladius of the Romans, or a curved slashing sword (Falcata). The light infantry carried a small round shield and several javelins.

Gallic infantry carried shields and javelins and fought in massed formations and relied heavily on their long, slashing swords. Both Spanish and Gallic tribes provided contigents of well-mounted brave, but undisciplined cavalry who's main tactic was an all out charge. Body armor was very unusual amongst the tribal people of Europe and helmets only slightly less uncommon. Ancient authors depict these warriors as ferocius in the first charge, but tired easily and were inclined to lose heart if things did not go their way. There's some truth in this, but on other occasions they showed that that these troops proved more stubborn that this statement allows.

It is normal to speak of the Carthaginian army as a force of mercenaries, but this is an oversimplification. The soldiers were raised in many different ways and included a variety of different motivations. Many contigents were not hired but provided by allies or states as part of a treaty. This seems to have been the case with the Numidian Kingdoms who enjoyed good relations with Carthage's noble families and were often allied by marriage.

Tribal and Numidian contigents were usually led by their own chieftans or princes and only unified when it came under Carthaginian command. The tribal contigents often formed a bond of loyalty to the army's general rather than the state it was fighting for. For example when it was rumoured that Scipio had left Spain, many of the tribes rebelled.

At the same time tribal armies were fiercely loyal to their chieftans and could fight against the same army they were serving a month earlier if it was so decided by their chief.

Source: The Fall of Carthage Adrian Goldsworthy