37 6 
PATAGONIAN EXPEDITIONS I PALAEONTOLOGY. 
Fibula, length ............ .164 
“ antero-posterior diameter of proximal end ..... .020 
“ “ “ “ distal “..... .0175 
Astragalus, length ........... .026 
“ width of trochlea . . . . . . . . . .019 
“ “ “ neck ......... .009 
Metatarsal I, length .......... .0245 
“ “ width of proximal end ........ .008 
“ “ “ “ distal “ . . . . . . . .0065 
Metatarsal III, length .......... .037 
“ “ width of proximal end ....... .0075 
“ “ “ “ distal “ . ...... .012 
CLADOSICTIS Ameghino. 
(Plates LII, Fig. 4; LIII, Figs. 3, 3 a, 10; LIV, Figs. 1, 3, 4, 10, 12; LV-LVIII; LIX, Figs. 
6-7^; LXI, Fig. 1.) 
Cladosictis Amegh. ; Enum. Sist. Especies Mami f. Fos. Patagonia Austral, 
p. 7, 1887. 
Hathliacynus Amegh. ; Ibid., p. 7, 1887. 
Anathermm Amegh. ; Ibid., p. 8, 1887. 
Proviverra (Rutimeyer) Amegh.; Revista Argentina, etc., I, pp. 149-150, 
1891. 
Dolichocephalic thylacynes intermediate in size between Amphipro- 
viverra and Prothylacynus. 
Dentition (Pis. LIV, fig. 1 ; LV, figs. 1, 3; LVI, figs. 1, 3; LIX, figs. 
6-7 
The median incisors (PI. LV, fig. 3) are laterally compressed, unlike 
the corresponding teeth in Dasyurus, Didelphys and A mphiproviverra. 
The remaining incisors, so far as preserved, have laterally compressed 
crowns, and increase regularly in size externally. The crowns of the 
lateral pair are triangular in cross section. In all the specimens examined, 
the incisors are badly worn, reducing the crowns to irregularly truncated, 
flattened columns. The canines are stout, laterally compressed blades, 
the posterior margins of which are almost straight, while the anterior 
margins are moderately convex. The anterior and median upper pre- 
molars are spaced in both species. The median and posterior premolars 
are spaced in C. petersoiii , unspaced in C. lustratus. The anterior pre- 
molar is separated by a short interval from the canine. Its crown is a sim- 
