He referred also to the nautiloid shell of the larva falling to one side.
The remarkable group of the Trilobites had precedence in order of time of the nautiloid shell-fishes.
Cephalic shield pointed behind; shell internal, chiefly membranous, with calcified nucleus, nautiloid; parapodia forming fins.
Any of various cephalopod mollusks of the subclass Nautiloidea, having a straight or coiled shell divided internally into a series of chambers of increasing size connected by a central tube. The nautiloids include the modern nautiluses as well as numerous extinct species dating back as far as the Cambrian Period.