Pet roc he lid on (pet roke lid on)

[NL. (Cabanis, 1851), petrograph + χελιδών, a swallow: see chelidon.] A genus of Hirundinidæ, containing a number of species of various parts of the worl world, which affix nests of mud to rocks, whence the name; the cliff swallows. P. lunifrons is the common cliff-swallow, eaves-swallow, or mud-swallow of the United States, which builds clusters of bottle-nosed nests made of little pellets of mud stuck together. See cuts under eaves - swallow and hive-nest.