Inferior gnathoschisis is an extremely rare anomaly. Search of the literature has revealed only three instances of this defect in man. Keith1 recorded a case in a full term infant (MacCormick's specimen in the museum at St. George's Hospital). Dupuytren2 mentioned a case of "median fissure of the lower lip and lower jaw." Wölfler3 described a similar case in which there was, in addition, a cleft tongue. Hamilton2 and Bland-Sutton2 each reported a case of partially cleft lower lip. The defect is apparently equally rare in the lower animals. Walker2 reported a median cleft of the lower lip, the lower jaw and the tongue in a calf. According to Keith the collection of examples of facial malformation in the museum of St. George's College includes only three specimens of median cleft of the lower lip and jaw; one from an ass, another from a