Antonio Sciarretta's Toponymy
Common remarks: the place-names have been put in the nominative case, an asterisk * means not attested, reconstructed form. The late place-names of probable Latin origin have not been included. The IE roots are in the form given by Pokorny's Indogermanische Wörterbuch. The links will be active when the single pages will be published, see the main page. For any comment, suggestion, email me.
Certainly non-Oscan are some place-names, distributed on the western part, at the borders with Latium and Campania, that preserve *kw or show an intervocalic *bh>b. These are likely related to Sicule and Latin in the so-called Weatern Italic branch.
From other place-names, distributed along the Adriatic coast, it is possible to assume a different, probably previous, linguistic stratum. This consists in one language characterized by a consonant shift. There is evidence of the voiced stops shifting to voiceless (*d>t, *g>k and presumably *b>p), and of the aspirated voiced stops shifting to voiced (*bh>b etc.). The voiceless stops were preserved or maybe, to complete the shift, they were aspirated, but this aspiration is not shown in the Latin sources, since Latin language had not aspirated voiceless stops in its alphabet. This unknown language is only a speculation. Conventionally, it will be referred to in the languages' page, as Picene (the so-called Picene alphabets seem to have had aspirated voiceless stops).
Even a stratum due to an A-language (that is to say, a language in which *o>a) seems to be possible, in order to explain some place-names with an unclear IE ablaut.