Hi Tim
Those units appear on the reference card from the first expansion but there are no stickers for them as yet they are not mentioed in the new unit types in this expansion section of the rule book.
Maybe they where taken out during final development but the reference card wasnt changed.
The only new unit type mentioned at
www.gmtgames.com/t-CandC4Details.aspx
is Cataphracts.
Imperial Rome is packed full of unique and interesting play concepts and new units: cataphracted cavalry, wagon laager forts, massed units of horse archers, light infantry tossing caltrops and more. Each of these concepts operates within the confines of the original system rules, with only slight modifications to reflect historical abilities and importance. So, rules-wise, if you own Commands & Colors: Ancients, you'll have no trouble learning the few new special rules. take from below
www.gmtgames.com/p-240-c-c-ancients-exp-...4-imperial-rome.aspx
I think the two units you mentioned are the only ones like that