PHISAMATI

The same fragment of 'Protogenes Decree' mentions another highly interesting tribe of Phisamiti:

«...the deserters informed that Galates and Scirii formed a union and gathered big forces, which will come in winter. Besides, Phisamiti, Scythians and Savdarati are looking for a fortified place being afraid of Galates´cruelty...» «Chrestomathy on Ancient World's History» edit. V. V. Struwe, vol. 2, "Uchpedgiz", Moscow, 1951. 

...which in another source is written differently as 'phisamati':

http://www.olvia.info/6-22.php

Again we have the impeccable Kartvelian (or, more exactly, Megrelian) toponymic structure which denotes not a nation, but a country:

PHIS + AM + AT + I 

Four Megrelian morphemes...

1. 'Phisi' (ფისი) means 'tar' (Margalitadze).
2. '-am', as was explained in Priam's article, is Megrelian adjective suffix that corresponds to Kartvelian '-ian', and which you will find a lot in Otari Kajaia's dictionary. So, 'phisami' means 'tarry'. 
3. '-at', as it had been said thousands times, is the Megrelian analogue to the Georgian toponymc '-et' suffix.
4. '-i' is the Kartvelian nominative case ending.

Overall, we have 'Phisamati'/'Phisameti' as 'country of the tarry (people)'.

And now the confirmation. The tarry people indeed used to live in that region under the name of 'smoliani' (exactly 'tarry' in Slav languages):

http://uk.wikipedia.org/wiki/Смоляни

It's a well-know South-Slav tribe.