422 
PATAGONIAN EXPEDITIONS I PALAEONTOLOGY. 
Mj, antero-posterior diameter . 
“ transverse “ . 
Depth of mandible below median premolar 
.001 
.0008 
.0022 
.0023 
.0022 
ii 
GARZONIA Ameghino. 
(Plate LXIII, Figs. 8, 8 a, 10-13.) 
Garzonia Amegh. ; Nuevos Restos Mamif. Fos. Patagonia Austral, pp. 
21-22, Aug., 1891 ; Revista Argentina, I, entr. 5a, pp. 307-308, Oct., 
1891. 
Phonocdromus Amegh. ; Enum. Syn., pp. 99-100, 1894. 
The genus Garzonia is represented in the Princeton collection by the 
left half of a lower jaw (No. 15,238), associated with parts of both fore 
limbs, referred provisionally to G. patagonica. 
Dentition (PI. LXIII, figs. 8, 8a). — The tip of the median incisor has 
been broken off, but enough remains to show that the enamel is confined 
almost entirely to the outer side of the crown. Six single-rooted, more 
or less pronate, vestigial teeth follow the enlarged incisor. Of these 
the first, fourth, fifth and sixth are preserved. The second and third are 
represented by roots retained in the alveoli. The antemolar formula of 
this individual is therefore nine, the highest on record among the Dipro- 
todontia. The constancy of this character may well be doubted. The 
median premolar and parts of both walls of its alveolus have been broken 
away, but enough remains to show the double-rooted character of the tooth. 
The posterior premolar is a large tooth supported on heavy roots, with the 
crown laterally compressed and, in some species ( Garzonia typica ), elevated 
considerably above the molar series. In No. 15,238, the enamel has been 
broken from the tip of the crown, which probably had a slightly greater 
degree of elevation than is indicated in the figure. The rather prominent 
heel of the posterior premolar is overhung by the anterior portion of M T . 
The molars are greatly worn, and the crown pattern, which appears to have 
been similar to that in Ccmolestes , almost obliterated (cf. PI. LXIII, figs. 
8a, 14^). The last molar is single-rooted, a character which distinguishes 
Garzonia from Halmarhipus and Ccenolestes. The crown has been broken 
off. In Mt the trigonid is somewhat higher than the talonid, as in Cceno- 
testes. This was probably true also for Mi and Mi, but has been obliter- 
