224 THE DESEADO FORMATION OF PATAGONIA 
MEASUREMENTS, SPECIMEN 3020 
Lower dentition, premolar 3, length 1 mm. 
Lower dentition, premolar 4, length 5 mm., width 2 mm. 
Lower dentition, molar 1, length 4 mm., width 2 mm. 
Lower dentition, height under pm. 4 6.5 mm. 
Caenolestinae 
- e ; nes aya Le, maic > > r sues 
The subfamily is distinguished by the formula 7—<—, 
pm. 4 not being enlarged, and the lower molars being 
tuberculo-sectorial. In the Deseado formation this group 
is only represented by a single species, based on a single 
tooth found by Ameghino. 
Pseudhalmarhiphus guaraniticus Ameghino 
P. guaraniticus Amegh., 1903, Anal. Mus. Nac. Buenos Aires, ser. 3, t. 2, p. 
83. 
Based on a single tooth, similar to those found in the 
Sanita Cruz, 
Abderitinae 
The subfamily is distinguished by the formula», 
the fourth premolar being enlarged into a sectorial tooth 
on the sides of which are vertical striae. The molars are 
buno-lophodont. The Deseado has yielded only a tiny 
form, designated Parabderites, which differs from the Santa 
Cruz genus Abderites in pm. 4, the same shape, by with 
few to no striae on its sides. 
Parabderites minusculus Ameghino 
P. minusculus Amegh., 1902, Bol. Acad. Nac. Cienc. Cordoba, t. 17, p. 43. 
The species as described by Ameghino is based on a 
lower jaw with pm. 3 to m. 3. The specific character is 
the lack of striae on pm. 4. No figure is given but the 
following measurements indicate the size. 
Lower dentition, premolar 3 to molar 3 g mm. 
Lower dentition, height of mandible under pm. 4 4 mm. 
