REFERENCES TO THE PLATES. 129 
Fig. 2. Antero-internal view of an anterior tooth, from Monmouth County, New Jersey. a, 
External surface of crown; 0, internal surface ; c, fang. 
Fig. 3. Antero-internal view of an anterior tooth, from Monmouth County, New Jersey, belonging 
to Rutgers College. a, External surface of crown; 3b, internal surface; c, fang. 
Fig. 4. Inner view of an anterior tooth, from Monmouth County, New Jersey. a, Inner surface 
of the crown; 6, impression of cavity for a successional tooth. 
Fig. 5. Small fragment of a jaw, with a tooth and portion of another, inner view, from Monmouth 
County, New Jersey. a, Internal surface of the crown exhibiting the divisional planes; b, portion 
of crown of the adjoining tooth; c, exserted portion of fang; d, portion of fang within alveoli and 
coossified therewith; e, three large cavities for successional teeth; 7, communication of the latter 
cavities with the pulp cavities of the teeth in use. 
Fig. 6. Tooth, with small attached. portions of the jaw, found with that of Fig. 5, and.from the 
same individual, Internal view. a, Inner surface of crown; b, exserted portion of fang; c, portion 
of fang coossified wit the interior of the alveofus; d, fragment of outer part of the jaw; e, large 
cavity, apparently for a pair of successional teeth; f, large pulp cavity. 
Fig. 7. Tooth, internal view, from Monmouth County, New Jersey. a, The inner surface of the 
crown, which is devoid of divisional planes; 6, fang without trace of coossific attachment. 
Fig. 8. Inner view of the crown of a shed tooth, from Monmouth County, New Jersey, belonging 
to Dr. C. Thompson. It resembles the corresponding part of a Crocodile tooth more than the 
ordinary forms of the Mosasaurus teeth. 
Figs. 9, 10. Two teeth, internal view, from Mount Holly, Burlington County, New Jersey. From 
the color and structural appearance the two teeth look as if they had been derived from the same 
individual. The crowns bear a close resemblance to the corresponding part of the teeth of the 
Crocodile. a, Impress upon the postero-internal surface of the fang of a cavity for a successional 
tooth. The specimen, represented by Fig. 9, is a shed crown, as proved by the excavated appearance 
of the base. 
Fig. 11.’ Shed crown of a tooth, from St. George’s, New Castle County, Delaware. Internal view. 
It strongly resembles a Crocodile tooth. 
Figs. 12, 13. Tooth of Polygonodon vetus, from Burlington County, New Jersey, from the collec- 
tion of Prof. Cook. 
Fig. 12. Posterior view. 
Fig. 13. External view. 
' 
PLATS: XxX. 
All the figures, representing teeth of Mosasaurus, are of the natural size. 
Fig. 1, Tooth, from Freehold, Monmouth County, New Jersey, belonging to Dr. C. Thompson. 
Inner view. a, The crown exhibiting divisional planes of the inner surface well-marked; b, the 
osseous fang, longitudinally furrowed, and exhibiting no trace of former attachment with the sides 
of the socket in which it was inserted ; ¢, impression of a cavity originally occupied by a successor 
to the tooth placed in advance; d, deeper cavity for a successional tooth. 
Fig. 2. Tooth, from Monmouth County, belonging to Rutgers College. Outer view: The crown 
exhibiting one of the acute ridges which separate the outer surface a, from the inner surface b; both 
the latter present well-marked divisional planes; c, the fang, which was coossified with its alveolus, 
a fragment of the jaw being seen at d. 
Fig. 3. The shed crown of a tooth, from near Woodbury, Gloucester County, New Jersey. Lateral 
view. a, Outer; 6, inner surface, separated by a sub-denticulated ridge, and both presenting divi- 
sional planes. 
Fig. 4. Tooth, from Monmouth County, New Jersey, from the same individual as those represented 
in Figs. 7-10, and Figs. 5, 6, Plate IX. Internal view. a, Inner surface of the crown, which has 
but ene carina ; b, exserted portion of fang; c, bottom of fang, which was coossified with its alveolus ; 
d, large cavity for a successional tooth. 
17 May, 1865. 
