186 ANCEIDE. 
the middle. That the male animal should be without 
a mouth and digestive apparatus, we certainly were not 
prepared to find, since the presence of the mandibles, 
though unusually placed, induced us to expect the 
existence of a prima via as much as we had deduced 
its absence, from finding those organs wanting in the 
female. 
The large lateral lobes of the cephalon are filled with 
muscles, which hold and move the powerful mandibles 
that can only exist as organs with which to grasp the 
female. 
From the facts which have now been observed, assisted 
by the elaborate labours of M. Hesse, we have arrived at 
the following conclusions :— 
Ist. That Anceus of Risso and other authors, with 
a large head and porrected mandibles, is the fully de- 
veloped male state of this genus. 
2nd. That Praniza of Leach and other authors, with a 
small head, is the female state, either in an unimpregnated 
or gravid state. 
8rd. That the larva form of the animals of both sexes, 
although closely resembling each other, may be distin- 
guished at a very early stage of their growth, even if not 
immediately after birth. 
We hope that the conclusions at which we have thus 
arrived will be tested by close observers. There are also 
some points of interest in the internal structure of these 
animals that have yet to be worked out. 
