I have two associated ungual phalanges, one of which corresponds to that figured by Ameghino as the third. It is high, laterally compressed, has a very rugose surface on either side, and a deep cleft in the end. This is 68 mm. long. The second ungual is very asymetrical, also laterally compressed, and with the point curved inward. I take it to be the fifth. The tibia, the tarsus, and the phalanges strongly suggest that this animal walked on the side of its foot. =Asmodeus scotti= Ameghino A. scotti Amegh., 1895, Bol. Inst. Geog. Argen., t. 15, p. 643. A. scotti Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 477. This species is not represented in our collection, but I reproduce Ameghino’s figure of the type, and of the milk dentition. Unfortunately his type figure is from the side and does not give all the desired information. [Illustration: Fig. 100. Upper and lower incisors, canines, and premolars—½ natural size, after Ameghino.] [Illustration: Fig. 101. Milk incisors, canine, and premolars and permanent m. 1—½ natural size, after Ameghino.] In the upper dentition, the small incisors, pitted on the crown, increase regularly in size toward the rear; and each has an external cingulum around the base. The canine is about twice the size of the adjacent incisor, and also has an external cingulum. The premolars increase regularly in size and also have at least an external cingulum. Figure 101 shows a dentition which Ameghino described as the milk set of _A. osborni_. At the same time he remarks the unusual character of the deciduous canine in being two-cusped. I think this set of teeth should be interpreted as deciduous inc. 2 to deciduous pm. 4, plus the permanent molar 1. With such an interpretation, we find the incisors normal, the canine normal though not as large as in the permanent set, and the two-cusped tooth is the first milk premolar. The last tooth in the series is considerably different from the premolars and is evidently permanent molar 1, which is about the size and character of this tooth in _A. scotti_, much too small to belong to _A. osborni_. This set of milk teeth differ from the permanent teeth in that the premolars do not have the anterior, inner and posterior cingulum, characteristic of the permanent dentition. The following measurements are taken from Ameghino: Upper dentition, inc. 1 to pm. 4 104 mm. Upper dentition, premolar 2, length 18 mm., width 25 mm. Upper dentition, premolar 3, length 20 mm., width 28 mm. Upper dentition, premolar 4, length 23 mm., width 35 mm. Upper dentition, molar 1, length 28 mm., width 39 mm. Upper dentition, molar 2, length 37 mm., width 44 mm. Upper dentition, molar 3, length 50 mm., width 48 mm. CHAPTER XI ASTRAPOTHERIA