SHELLS ALLIED TO NAUTILUS. .‘KM 
It is a cui'ious fact, that contrivances, similar 
to those which existed in some of the most early 
forms of Ammonite, should have been again 
adopted in some of the most recent species of 
fossil Nautili, in order to afford similar com- 
pensation for weakness that would otherwise 
have been produced by aberrations from the 
Oormal structure of the genus Nautilus. All 
this seems inexplicable on any theory which 
'^'ould exclude the interference of controlling 
Intellig ence. 
SECTION VI. 
CHAMBEUED SHELLS ALLIED TO NAUTILUS 
AND AMMONITE. 
have reason to infer, from the fact of the 
tecent N. Pompilius being an external shell, 
that all fossil shells of the great and ancient 
family of Nautili, and of the still more nume- 
^’oiis family of Ammonites, were also external 
shells, inclosing in their outer chamber the body 
®n(I of N. Zic zac; like them also the margin was simple and 
^®stitute of fringed edges. The A. nodosus (PI. 40, Figs. 4 and 
which is peculiar to the early Secondary deposits of the Miis- 
‘^I'el-kalk, ofiers an example of an intermediate state, in which 
^ fringed edge is partially introduced, on the descending or 
'”'vard (>ortions only, of the lobated edge of the transverse plates. 
