Does Chill Touch combine with a natural touch attack?

Question

In Pathfinder, a lich has a natural touch attack that deals negative energy damage. If a lich casts Chill Touch and touches an enemy, does he deal his normal touch attack damage plus the 1d6 damage from Chill Touch, or does the 1d6 damage from Chill Touch replace his normal touch attack damage?

Note: The question is inspired by this character from the Kingmaker adventure path, an unusually low-level lich who has Chill Touch as one of his few damaging prepared spells (his published tactics seem to think that he can deal damage by channeling negative energy, forgetting that necromancers can only do that to Turn/Control Undead).

Answer 1

Yes, the lich can deliver touch spells via his touch attack

The full rules for Touch Spells in Combat are a little vague, but they do indicate that a touch spell can be delivered via an unarmed attack or natural attack. The stat block provided for this specific lich shows his touch attack normally, in the Offense block, without any iterative attacks, and with a bonus on the damage equal to one and a half his Strength bonus. This heavily implies the touch attack is considered to be a Natural attack, even if the damage type is unspecified, and even if the attack can also paralyze (much like a Slime Crawler has a paralysis effect tacked onto it's tentacle natural attack).

Answer 2

I would have to say it depends on what the Lich is trying to do.

The touching of a creature after casting Chill Touch is a free action when done in the same round. Using a lich's touch attack is a standard action. If the lich merely touches an enemy as part of that free action, I would say it doesn't also deliver the touch attack damage.

However, if it touches the enemy with the intent of delivering its touch attack damage, then it will also discharge the Chill Touch spell as well and deal both damages.

Holding the Charge: If you don't discharge the spell in the round when you cast the spell, you can hold the charge indefinitely. You can continue to make touch attacks round after round. If you touch anything or anyone while holding a charge, even unintentionally, the spell discharges. If you cast another spell, the touch spell dissipates. If the attack misses, you are still holding the charge.