Tertiary. ] PALAONTOLOGY OF VICTORIA. [Mammalia. 
part; beyond this transverse swelling the cavity is still more shallow than the pos- 
terior portion, bounded on the narrow, obtusely rounded front by the thick obtuse 
continuation of the outer margin slightly stopping the Eustachian canal; a slight 
flattening of the inner side, forming an obtuse angle with the flattened under surface, 
slightly interrupts the regular involute curvature of the surface, and there is a 
slightly concave sinus in this side opposite the internal transverse swelling in the 
cavity. Length, about 3 inches; greatest width, 2 inches; greatest depth at centre 
of greatest convexity of involute portion, 1 inch 4 lines to 5 lines; greatest width 
of involute part, 1 inch 3 lines. 
This, which is the rarest of the three species of Cetotolites, was 
the first which I had seen; one of the two specimens in the 
National Museum collection having been presented to me by the 
late Rev. Mr. Legge, of Brighton, to whom I have dedicated the 
species as a slight memorial of his zeal in geological enquiries. It 
is distinguished from the others by the great size and gibbosity of 
the involute part, the thick obtuse slightly elevated outer over- 
arching plate, the complete absence of notch or bilobation in the 
posterior end, and the total absence of projecting process on the 
upper posterior surface of the involution for attachment to adjacent 
bone. 
Rare in the Miocene Tertiary strata of Waurn Ponds quarries, 
near Geelong. 
EXPLANATION OF Ficures. 
Plate LIV.—Fig. 1, specimen, imperfect at anterior outer edge, viewed from above, natural 
size. Fig. la, same specimen viewed from behind, showing the shallow concavity in under 
surface. 
Pirate LIV., Fie. 2. 
CETOTOLITES PRICEI (McCoy). 
Descrriprion.—In size and general form resembling C. Leggei, but distinguished 
by a large rugged oblique projection on the upper posterior portion of the involute 
convexity for articulation with the adjacent skull bones; the more distinct bilobation 
of the posterior end and deeper mesial concavity on posterior end of under surface 
leading from the sinus of the slight bilobation ; the inner outline is straighter from 
the posterior portion of the involute part not being so convex, or pyriformly swollen ; 
outer inarching plate very much thinner and extending much higher so as to form a 
much deeper cavity; the oblique thickened swelling dividing the deeper posterior 
portion of the cavity from the anterior is less prominent, and the anterior cavity at 
the Eustachian semicircularly rounded anterior end is larger and deeper, the raised 
bounding margin continued from the outer wall being much thinner. Length, 2 
inches 8 lines ; greatest width, 1 inch 11 lines; greatest depth, 1 inch 1 line; greatest 
width of involute part, 1 inch 1 line, 
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