Psionic Energy Ray and DC

[equestech]

I am new to PFRPG and especially to psionics. I am trying to understand how DC relates to psionic attacks. I am looking specifically at Energy Ray, which is listed as a Psi-Like Ability for Small Psionic Elementals as follows.

"Psi-like Abilities (ML 2nd): At will—detect psionics, distract (DC 13), psionic daze (5 HD, DC 13*)
3/day—energy ray (2d6, DC 13*), thought shield.

A psionic elemental has a number of psi-like abilities. Its manifester level (ML) is equal to its Hit Dice unless noted otherwise. The save DCs are Charisma-based for all psionic elementals. Psi-like abilities augmented for the elemental's manifester level are noted with an asterisk."

So according to this the DC for Energy Ray is 13 and is Charisma-based. But if you look at the description of Energy ray it indicated that there is no saving throw. So how is the DC 13 applied?

[Quintain]

The DC calculation is basically "standard notation". If the power allows no saving throw ignore it for the purposes of saves.

[Saethori]

Also take note that psionics are a third party creation, and thus this belongs in the third party forums. I flagged it accordingly.