Congenital atresia of the tricuspid orifice is a rare condition and to make this anomaly compatible with life, it becomes necessary that there be patent foramen ovale or at least an opening in the interauricular septum and that the two ventricles communicate. Associated with these, there may also be a patent ductus arteriosus. When the conditions mentioned above are the only anomalies, such a case is spoken of in the literature as an uncomplicated case. Of such we have been able to find records of eight cases to date. As complicated cases may be considered those in which there are further anomalies, such as transposition of vessels. The case which we have had under observation is as follows: E. L., 8½ months old, was admitted to Michael Reese Hospital Nov. 5, 1914, and died Nov. 12, 1914, after having been under our observation for about four months. The child had