The aim of the article is to present the attestations of contemporary Polish surnames of Lithuanian origin which are absent from the dictionary of Lithuanian surnames (“Lietuvių pavardžių žodynas”, LPŽ), excerpted from the anthroponymic index card files that have been stored in the Lithuanian Language Institute in Vilnius and continually enlarged for several decades now. The files contain data excerpted from historical sources of the 16th to 19th centuries and consist of about 200,000 index cards (the actual number of excerpted anthroponyms is lower since some recur in various sources). Due to space limitations, generally only directly attested names have been included in the article, to the exclusion of those whose relationship with the researched name can be inferred rather than considered proven. Each listed attestation of an anthroponym (probably not in all cases an already established hereditary surname) is accompanied by information concerning its location and year (or time bracket), wherever available in the card index file. Given names or other details (e.g. the role of the person mentioned in documents, such as godmother in the data excerpted from baptismal registers) have only been included occasionally, if there was some reason to do so.
Many performing artists in the interwar period in Poland assumed stage names, which were considered a tool of promoting one’s image, but also served other functions, such as the concealment of identity. Over two hundred such pseudonyms — together with the respective artists’ birth names — have been collected and analysed in the article. Approximately in the case of half of them was the original given name retained, and only the surname underwent a change. The comparison of the assumed names with the real ones shows that many names were shortened, and/or made to sound foreign or exotic. Minority surnames — Jewish/German, Russian, Ukrainian — were frequently made to sound Polish, while the Polish ones were foreignised (to make them look English, Italian, French) or vaguely exoticised.
The article presents the most frequent surname in Lithuania — Kazlauskas. Referring to the article “Mysterious Lewandowski” by K. Skowronek (2000), an attempt has been made to account for this frequency in three various ways. First, the principles behind the quantitative structure of anthroponomasticons (Zipf’s law) and the loss of surnames (genetic drift) are discussed. Then the Slavic origin of the surname under consideration has been highlighted as a typical trait of the majority of surnames in Lithuania. In connection with this fact, it has been stressed that caution must be exercised in proposing a thesis on its origin as a translation from Lithuanian on a mass scale, since this thesis requires plentiful empirical evidence. Finally, the etymology of the name is analyzed. Morphologically it is a typical surname derived from a toponym. This supposition is additionally supported by the existence in Poland of numerous localities called Kozłów, Kozłowo or similar name; these in turn are most likely to have been derived from appellative-based personal names of their owners or inhabitants, such as Kozieł.