The neume-like signs found between text lines in many lectionaries are often overlooked. Together with punctuation, these melodic lection marks helped readers to determine how and where to begin the melodic cadences that marked the ends of phrases. Using the Dominican exemplar manuscripts of c. 1260--the earliest books to include both melodic lection marks and pitch-specific notation indicating how to conclude each type of phrase--this article demonstrates the function of each sign and thereby reveals the relationship between melodic lection marks and the reading of Mass lections. Based on a study of over 60 manuscripts used for public reading, this article traces the emergence of melodic lection marks in the early Middle Ages, examining the ways in which they were systematised in Cistercian, Dominican and Sarum books.