Lower dentition, length from inc. 1 to m. 3 455 mm. Lower dentition, incisor 2, length 22 mm., width 22 mm. Lower dentition, canine, ant. post. diam. at alveolus 52 mm. Lower dentition, canine, trans. diam. at alveolus 26 mm. Lower dentition, diastema from c. to pm. 3 116 mm. Lower dentition, premolar 4, length 28 mm., width 26 mm. Lower dentition, molar 1, length 43 mm., width 28 mm. Lower dentition, molar 2, length 58 mm., width 32 mm. Lower dentition, molar 3, length 70 mm., width 36 mm. Height of mandible under molar 3 83 mm. The scapula is a very long heavy bone, with a narrow blade, and a high spine which has its upper margin thickened so as to appear like a banister rail. We found one complete scapula and a second incomplete one associated with it, which corresponded in all ways to the first one. [Illustration: Fig. 104. Lower jaws—⅕ natural size.] [Illustration: Fig. 105. Dorsal view of right scapula—⅕ natural size.] [Illustration: Fig. 106. Right humerus, posterior aspect—⅕ natural size.] [Illustration: Fig. 107. Left femur, posterior side—⅕ natural size; outline of upper portion after Gaudry from Astrapotherium magnum.] The following measurements are taken from specimen No. 3328: Scapula, greatest length 694 mm. Scapula, greatest width 283 mm. Scapula, glenoid fossa, ant.-post. diameter 130 mm. Scapula, glenoid fossa, transverse diameter 90 mm. Scapula, height of spine 120 mm. Scapula, width of enlarged margin of spine at the lower end 170 mm. Scapula, width of margin in middle 45 mm. The humerus was associated with the two scapulae mentioned above, and is complete. For such a large animal, its length is excessive, greater than that of the species assigned by Gaudry to _P. herculeum_ which species has a skull larger than that of _P. holmbergi_. Humerus, greatest length 720 mm. Humerus, greatest width across proximal end 248 mm. Humerus, least diameter of shaft 78 mm. Humerus, width across the epicondyles 220 mm. Humerus, width of trochlea on distal end 125 mm. The femur which Gaudry figures as belonging to _Astrapotherium magnum_ corresponds, as far as the distal end will admit comparison, with the one which we found in the Deseado beds, so that in restoring the outline of the missing parts, I have based it on this _A. magnum_.