Lateral view of embryo No. 6520 stage 17 demonstrating characteristic development, i.e. the presence of the lateral nasal wing, the prominence of the three-hillock plate behind the hyomandibular groove, the disappearance of pharyngeal arch 3, the presence of digital rays of the hand plate, and the absence of toe rays except for the prominence of the great toe.
O'Rahilly and MÃ¼ller, 1987 Fig. 17-2
Source: The Virtual Human Embryo.