Figure 2: (A) Equine fetus at 40 days. Observe nostrils with the nasal diverticulum (ND) closed, upper lip (UL), and lower lip (LL). (B) Rostral region of the head of the equine fetus at 110 days. Note the open external nose with the nasal diverticulum (ND), upper lip (UL), lower lip (LL), and oral cavity (*). (C-F) Development of the nasal cavity between 40 and 110 days of gestation. (C) At 40 days the nasal septum (NS), nasal concha (NC), ventral nasal concha (VNC), and ethmoid concha (EC) are observed. (D-E) Observe at 80 days (D) and 110 days (E) the nasal concha (NC), ventral nasal concha (VNC), ethmoid concha (EC), cricoid cartilage (CC), thyroid (Ti), trachea (Tr), and epiglottis (Ep). (F) Detail of the dorsal region of the nasal concha (NC), ventral nasal concha (VNC), ethmoidal concha (EC), nasal septum (NS), hard palate (HP), soft palate (SP), choana (Co), and tongue (To). The dorsal nasal concha has a right fold line (r) and a dorsal nasal meatus (*). The ventral nasal concha has alar (a) and basal (b) folds, showing the middle nasal meatus (**).