Tertiary.] PALAONTOLOGY OF VICTORIA. [ Vertebrata. 
distinguished from the Carcharias of the present seas, even when 
only the teeth can be examined, by the absence of the conical 
cavity in the base. The present species, even as_ originally 
restricted by Agassiz, is one of the most abundant and charac- 
teristic Miocene Tertiary fossils of every part of Europe and 
America in which strata of this age exist, and I recognized it 
amongst the Australian beds to which I assigned Miocene and 
Oligocene ages with great astonishment, from this evidence of its 
world-wide distribution in the Tertiary period. 
The most minute comparison fails to indicate the slightest 
difference between our Victorian specimens and those from the 
well known Miocene Tertiary beds of Biinde, in Westphalia ; they 
also agree perfectly with those from the supposed Eocene strata of 
South Carolina. On the convex inner face a small triangular space 
at the base is not covered by the thick polished ganoine which 
extends to the root on the outer face, as is common in the genus. 
The species is easily distinguished from the C. megalodon (Ag.) 
by the centre cusp being much narrower in proportion to its length, 
and by there always being a distinct pair of short, obtuse, strongly 
serrated, lateral cusps, one on each side of its base. 
Not uncommon in Miocene Tertiary sands of Bird Rock, near 
Geelong. 
EXPLANATION OF FIGURES. 
Pirate XI.—Fig. 2, specimen presented by Mr. Butler from the Miocene Tertiary of Bird 
Rock, near Geelong, natural size, viewed on the inner side, showing space bare of ganoine at 
_ base of crown. 2a, side view of same specimen. 2, portion of lateral serration magnified. 
Fig. 3, inside view of another specimen having the lateral cusps smaller. 
Puate XI., Fic. 4. 
CARCHARODON MEGALODON (Ace.). 
Descrriprion.—Teeth very large, of one broad triangular cusp, without lateral 
cusps ; cutting edges finely serrated ; flat outer surface, with a few irregular longi- 
tudinal sulci on basal half; inner face smoother, convex; root of moderate depth, not 
deeply bilobed. Dimensions of figured specimen—height of crown, 2 inches 2 lines ; 
width of base, 2 inches 6 lines; thickness, 8 lines; seven serratures in 3 lines on 
middle of cutting edge; depth of root, 11 lines. 
REFERENCE.—C. megalodon + C. rectidens (Ag.), Pois. Foss., vol. 38, t. 29. 
roy B 
