16 
Ca^e 17. 
Case 18. 
Here is a cast of a Nautilus shell in pure gypsum or 
selenite (Ca S0 4 +2H 2 0) ; through the transparent 
mineral infilling can be seen the median siphuncle 
preserved in natural position. 
Fig. 17. Fragment of a Fossil Nautilus. — N. allifrons, showing interior 
of chamber filled with transparent gypsum, and with the Siphuncle in 
position. 
Miocene. Murray Cliffs, South Australia. 
Here are shown extinct forms of Cuttle-bones. Spir- 
ulirostra is a very rare Miocene genus which 
is known to occur in only two other localities in the 
world. Notosepia is a fore-runner of the common 
Sepia and has a very strong and thick point or guard. 
In this case is also shown a fine series of Sharks’ 
teeth, mostly of Miocene age, as well as a remarkably 
preserved fossil imprint of a Bird’s feather in ironstone. 
