Geography in Early Judaism and Christianity: The Book of Jubilees - Google Buchsuche-Ergebnisseite
von James M. Scott - 2002 - Religion - 337 Seiten
Ariacins, Britons, Germans, Dacians. Sarmatians. Scythians and Ethiopians, especially those "on the other side of the river" |Zeph. ...
books.google.de/books?isbn=052180812X...

Here's a Latin text and an English translation:

sic et nondum est praedicatum esse evangelium apud omnes Ethiopas, maxime apud eos, qui sunt ultra flumen; sed nec apud Seras nec apud **Ariacin**" [Orientem, edd., but he probably means <gk>A)riakh/</gk>, a region on the western coast of India] [[13]] "audierunt Christianitatis sermonen. quid autem dicamus, de Britannis aut Germanis, qui sunt circa oceanum, vel apud barbaros, Dacos et Sarmatas et Scythas, quorum plurimi nondum audierunt evangelii verbum, audituri sunt autem in ipsa saeculi consummatione.

For we are not told that the gospel has been preached among all the Ethiopians, particularly among those who are on the other side of the River; nor among the Serae, nor in Ariace, has the tale of Christ been heard. But what shall we say of Britain or Germany, on the seaboard, or the barbarians, the Dacians, the Sarmatae, and the Scythians, most of whom have not yet heard the gospel, but are to hear it at the consummation of the ages?
ccat.sas.upenn.edu/rs/rak/courses/535/Harnack/bk4ch1old.htm


30/ Compare, however, the passage from Origen already quoted on p. 13: "Nec apud Seras nec apud **Ariacin** audierunt Christianitatis sermonem." -- Note that the first Protestant history of missions, published in Germany, was devoted to India, viz., M.V. La Croze, Hist. du Christ. des Indes, 1724 (cp. Wiegand in the Beiträge z. Förd. christl. Theol., 6.3. pp. 270 f.). La Croze, however, hardly touches the primitive age, as he regards the legends about Thomas as unauthentic.
ccat.sas.upenn.edu/rs/rak/courses/535/Harnack/bk4ch3-3-142.htm

This is the nearest I have found to an explanation.


--------------------------------------------------
Note added at 2 hrs (2008-12-15 22:48:55 GMT)
--------------------------------------------------

Ariace is mentioned here as one of 'two places of the hither India':
... of trade between' Ariace and ... of a white colour, and brittle, drank by the people of India. ...
books.google.co.uk/books?id=Z7wRAAAAYAAJ...

So it seems that these Ariacins were the people of a place known as Ariace, Ariake, depending which spelling you use. I believe this is the name given in my link, in slightly garbled Greek: <gk>A)riakh/</gk>.

Rachel's answer sent me on this further bit of research. I was hoping to find out more about Origen's Commentaries (ideally, the original Greek text), but obviously it's not so easy. Bear in mind that the Latin text is a translation or Origen's original Greek, and different editors may have different opinions on the correct reading of the Latin and/or Greek text. The passage quoted by Rachel is presumably a translation of a Latin version that uses the word 'Orientem', either in the text itself or as an editor's gloss on the word Ariacin.

--------------------------------------------------
Note added at 2 hrs (2008-12-15 23:07:36 GMT)
--------------------------------------------------

Places in India:

More factually, Periplus Maris Erythraei 14 mentions among. exports from Ariace and Barygaza (Broach) µλι τ καλα´µινον τ λεγµενον. ...
www.oup.co.uk/pdf/0-19-814698-1.pdf

That's it, odd bits of evidence, for what they're worth.

--------------------------------------------------
Note added at 12 hrs (2008-12-16 09:07:50 GMT)
--------------------------------------------------

It turns out there are many references to Ariaca, which is probably the Latin version of the name Ariace. See, for example:

http://en.wikipedia.org/wiki/Periplus_of_the_Erythraean_Sea

- and click on the map.

<gk>A)riakh/</gk> (in my ref. above) probably represents the Greek spelling of the place name (Αριακη) used in Origen's original text.

There are some questions I would put to classical/post-classical scholars: in particular, is 'Ariacin' a Greek accusative (Αριακην) that has been transferred into Latin?
My theory: 'Ariacin' is a place name (in the accusative case) used in the Latin translation of Origen's Greek. Later, in other languages (in translations from Latin), 'Ariacin' was turned into a plural and used as the name of the people.

The word 'Ariacins' may be used in a few sources, but I think there's a case to be made for calling them 'the people of Ariaca' (or 'Ariace').