Marsyas and from their bladders spouted a highly seasoned sauce upon fish
which were swimming about as if in a tide-race."

German scholars have adopted the doctrine that Marsyas belonged to that
mythological group which they designate as "Schlauch-silen" or, as we
would say in English, "Wineskin-bearing Silenuses." Their hypothesis
seems to be based upon the discovery of two beautiful bas-reliefs of the
age of Vespasian, which were excavated near the Rostra Vetera in the
Forum. Sir Theodore Martin has a note on these bas-reliefs which I quote
in extenso:

"In the Forum stood a statue of Marsyas, Apollo's ill-starred rival. It
probably bore an expression of pain, which Horace humorously ascribes to
dislike of the looks of the Younger Novius, who is conjectured to have
been of the profession and nature of Shylock. A naked figure carrying a
wineskin, which appears upon each of two fine bas-reliefs of the time of
Vespasian found near the Rostra Vetera in the Forum during the
excavations conducted within the last few years by Signor Pietro Rosa,
and which now stand in the Forum, is said, by archaeologists, to
represent Marsyas. Why they arrive at this conclusion, except as
arguing, from the spot where these bas-reliefs were found, that they were
meant to perpetuate the remembrance of the old statue of Marsyas, is
certainly not very apparent from anything in the figure itself."
Martin's Horace, vol. 2, pp 145-6.

Hence German philologists render "utriculis" by the German equivalent for
"Wineskins."

"The Romans," says Weitzius, "had two sources of water-supply, through
underground channels, and through channels supported by arches. As