Liquescentes are signs which derived from the basic and ornamental forms. Their modification indicates that the consonant of the text syllable is pronounced as a semivowel and the last notes of the liquescent neume will be sung with the sound of semivowel. Usually these semivowels are fricativa, nasals and liquida. Looking at the syllable used with liquiscent neumes, we can learn how the final consonants were pronounced in the local Latin pronounciation.

St Gall
epiphonus (pes liquescens):
cephalicus (clivis liquescens):
Other semivowel forms: