Roman Phalangites?

[Urselius]

Is the reference at Stasbourg to a testudo, this passage?

XVI., 12, 49: ...miles instar turrium fix firmitate consistens...

which my Loeb translates as ...stood their ground fast and firm, like towers...

And makes the note that although Turres was also a military formation, here the word is being used in its literal sense.

No, it's:

Amm. Marc. 16.12.36, 44
scutorum obicibus vertices tegens … nexamque
scutorum compagem, quae nostros in modum testudinis tuebatur,
scindebant ictibus gladiorum assiduis

“by incessant sword blows broke asunder the tightly-bound structure of shields, which protected our men like a testudoâ€