I now share your suspicion, having looked it up in the online Pauly (http://www.brillonline.nl/subscriber/uid=1506/entry?entry=bnp_e1207080&fields_1=heading&refine_editions=bnp_bnp&search_mode_1=%2B&row_id=1&result_number=3&search_text_row_1=thebes#hit), which gives an altogether different Egyptian name as the source (Coptic Čēme; Egyptian something or other which the character encoding garbles).