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Carnegie No. 5960 (figs. 8-3 to 8-12). Important specimen described by Heuser (1932b). Hysterectomy. Chorion, 15 x 14 x 9 mm. Embryonic disc (narrow type), 1.25 x 0.68 mm (in straight line); 1.53 x 0.75 mm (by flexible scale). Pri- mitive streak, 0.5 (0.44?) mm. Primitive node, 0.2 (0.06?) mm, slightly caudal to midpoint of embryonic disc. Notochordal process, 0.42 mm (George, 1942). Notochordal canal (about 0.4 mm) opens ventrally. Prechordal plate, 0.15 mm. Florian (1934b), however, believed that the prechordal plate was situated further rostrally than shown by Heuser. Angioge- nesis in umbilical vesicle, body stalk, and chorion. Angioge- nesis in chorion described by Hertig (1935). Neural groove. Presumed age, 18 days. Dorsal and median projections pub- lished (Heuser, 1932b, figs. 33 and 47; Mazanec, 1959, fig. 63).