In the medial angle of the eye, a reddish shallow reservoir of tears, the lacrimal lake, can be observed. Within the lake is the lacrimal caruncle, a small mound of moist modified skin. Lateral to the caruncle is a semilunar conjunctival fold, which slightly overlaps the eyeball. The semilunar fold is a rudiment of the nictitating membrane of birds and reptiles. When the edges of the eyelids are everted, a small pit, the lacrimal punctum, is visible at its medial end on the summit of a small elevation, the lacrimal papilla.