44 “TERRA NOVA” EXPEDITION. 
comprises a single species, VV. argentina, Ameghino,* from Patagonian deposits that 
were at first stated to be Cretaceous, but may prove to be Miocene. 
In Miolania (Fig. 8, B) the skull, seen from above, is somewhat oblong in form, 
with the snout broadly rounded. The dermal bosses all have the appearance of separate 
elements. On the upper surface may be recognised a large but low parietal pair ; 
behind them is an occipital pair that project backwards, and in front of them a 
smaller frontal pair mesially, and ‘a postfrontal pair laterally. A pair of subconical 
bosses, rounded or ovate in transverse section, on each side of the parietal pair, project 
as lateral “horns”; a much smaller pair are placed directly in front of them. Other 
features of the genus that may be mentioned are that the praemaxillaries have a 
median pit for the reception of the symphysial beak of the mandible, that the 
palatal extensions of the praemaxillaries and maxillaries bear two sharp ridges within 
Fie, 8.—Skulls of A, Niolamia argentina, and B, Miolania oweni, seen from above. In B the position of 
the anterior margin of the praemaxillaries is indicated by a dotted line. 
and parallel to the margin of the upper jaw, that the nasals project beyond the 
praemaxillaries, and that there is a bony internasal septum. 
In Miolamia (Fig. 8, A) the skull is nearly triangular in outline, with the snout 
more acute than in Miolania. The bosses differ considerably from those of Miolania, 
expansions, the lateral “horns” are broad and flat, triangtlar im section, and have no 
smaller pair in front of them. Further differences from J/iolania are that the prae- 
maxillaries are not pitted, the mandible is not beaked, the upper jaw has a single 
blunt intramarginal ridge, the nasals do not project beyond the praemaxillaries, and 
there is no internasal septum. 
These differences have already been pointed out by Dr. Smith Woodward (Proc. 
Zool. Soc. 1901, 1, pp. 174-176), but he has not insisted on them so much as on 
* Woodward, Proc. Zool. Soc., 1901, 1, p. 170, pls. xv—xvuil. 
