Tertiary. ] PALZONTOLOGY OF VICTORIA. [ Vertebrata, 
Prate XI., Fra. 1. 
SQUALODON WILKINSONI (McCoy). 
[Genus SQUALODON (Grar.) = PHOCODON (Ae.). (Sub-kingd. Vertebrata. Class 
Mammalia. Order Cetacea. Fam. Zeuglodontide.) 
Gen. Char.—Molar teeth, with a semi-elliptical crown, strongly compressed laterally, the 
cutting edge divided into semi-elliptical lobes in one plane, the middle one largest, the lateral 
gradually diminishing to the anterior and posterior ends; enamel longitudinally marked with 
small irregular ridges ; root with two or three fangs. ] 
Description.—This species is founded on one of the hindmost molars, having 
a compressed semi-elliptical crown 9 lines high, base 11 lines long and 5} lines 
thick ; middle cusp bent moderately backwards; anterior convex edge irregularly 
serrated and divided into unequal cusps, the smaller about one-third from the top, 
and the larger one-third from the bottom of that edge; posterior shorter edge 
divided almost equally into three larger cusps, the lowest smallest, the two upper 
nearly equal and much larger, being about half the width of the middle cusp. 
Surface longitudinally marked with coarse rough very irregular sulci, and small 
granular angular ridges and strie. Root bilobed below the upper half-inch, with 
incurved end; length of bilobed root, 1 inch 9 lines. 
The American Eocene Zeuglodonts, as well as the Malta Miocene 
Squalodon or Phocodon molars, constituting the New and Old 
World types of those extraordinary extinct carnivorous whales 
forming the family Zeuwglodontide, are larger than .the present 
species. The Zeuglodonts differ remarkably in the roots of the 
molars forming two widely separated fangs divided from each other 
nearly from the crown, and but little exceeding the crown in depth ; 
each face of the crown is indented by an extension of the depres- 
sion corresponding with the separation of the fangs. While in this 
fossil the root is very long, single, or only marked with a shallow 
sulcus on each side for the greater part of its length, only slightly 
extended to the crown. In these respects the S. Wilkinsoni most 
nearly resembles the hind molar of the Squalodon Grateloupi 
(Gervais) of the French Miocene beds near Bordeaux ; from 
which the Australian species is distinguished by its rather smaller 
size and peculiar proportions. The great proportional length of 
the roots indicates a greater proportional depth and strength of jaw 
than in the European species. The sole species of Syualodon pre- 
viously known is found in the Miocene Tertiary beds of Léognan 
fh te. 
