The correct spelling of the word "tarsis" is actually "tar-sis," with the emphasis on the first syllable. The pronunciation is /ˈtɑː.sɪs/ in IPA phonetic transcription. Tarsis is often misspelled with an additional "r" as "tarrsis," which could be due to the similar sound and spelling of the word "terror." However, it is important to pay attention to the correct spelling and pronunciation of words in order to effectively communicate and avoid confusion.