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bina, or Vacca, and which he thinks may be, perhaps, the same fish 
of which Aldrovandus speaks, Lib. 3. Cap. 52. Scilla gives a repre- 
sentation of the head and jaws of this fish, in which the agreement 
with the jaws described by Spallanzani is very evident. Plate XVIII. 
Fig. 10, is a fossil tooth of this species from my collection, which is 
very small. Fig. 11, is one figured by Scilla ; and each exactly agree, 
in form, with those of the recent fish both of Scilla and of Spallanzani. 
It is worthy of observation, that the triangular Glossopetrae are never 
found attached to any bony substance ; a circumstance confirming the 
opinion of their having originally been the teeth of fishes of the genus 
Squalus. The teeth of this genus, as has been some time since remarked 
by Scilla, and very lately by Spallanzani, not being placed in bony 
sockets, but implanted in a hard and fungous flesh ; and which, de- 
caying by putrefaction, allows the teeth to become detached. 
Conichthyodontes striati. These rare fossils are very exactly de- 
scribed, by M. Walch, as being of a conical form, round on all sides, 
with the superior termination, as it were, truncated ; and the whole 
surface of the teeth so covered with longitudinal striae, as to give them 
somewhat of the appearance of a Dentalite. These are sometimes 
found in the quarries of Chippenham, and of other parts of Wiltshire 
and Oxfordshire. One of these fossils is represented Plate XIX. Fig. 4. 
The straight or slightly bent conical teeth, Conichthyodontes recti 
teretes, have been termed Plectronitce and Rostragines ; and, indeed, 
are frequently called birds’ bills by the quarrymen who find them. 
Plate XIX. Fig. 8. 
The teeth of which I have hitherto spoken may be considered as 
being of the class of Incisores, and as being of the most decided kinds. 
There are others, which differ from these in their forms ; but so 
little, as not to require further notice here : such are those, which 
display little degrees of variety of curvature, or which have suffered 
some change of figure from accident. 
The molar teeth, which are placed in the back part of the jaws, 
