Of the snake called boas. The boas is a snake found in Italy; it is of a vast weight; it follows flocks of cattle and of gazelles, fastens on their udders when they are full of milk and sucking on these, kills the animals; from its ravaging of oxen, bos, it has got its name boas. Of the iaculus fly’ (Pharsalia, 9, 720). For they spring into trees and when anything comes their way, throw themselves on it and kill it. As a result, they are called iaculi, ‘javelin-snakes’.