402 APPENDIX, No. II. 
of the sac, immediately above the branchiz, on each side, is a 
small, short, fleshy tubercle, which fits into an excavation on 
the opposite side of the sac. This character, which, with 
slight modifications, is common to this genus, to /oligo and sepia, 
does not exist in the polypus.* 
Although the superior arms are stated to perform such diffe- 
rent functions from those of the polypus, yet they are supplied 
in the same manner, and from the same source with nerves. 
The muscles of these parts were in too contracted a state, to 
enable me to ascertain if they were in any degree different 
from those in the same parts of its kindred genus. 
The general form of the body of this species of ocythoé is the 
same as that of the common polypus, and it is covered by the 
same integuments, without any surface adapted either to adhere 
to, or to secrete, the shell in which it is found. The sexes dif- 
fer as in the polypus. 
OcytTHor CRANCHII. 
O. corpore purpureo-punctato, brachiis subtus cerulescente- 
griseis; superioribus membrana spongeosa pallida maculata. 
The superior arms are generally attached to the side of the 
membranes (fig. 5. Pl, XII.); but in one specimen the mem- 
branes adhere only by their base, below the apex of the arm, fig, 
6. The membrane is subject to great variation in size and form, 
and is often different on the arms of the same individual. 
One male only was sent home, all the others were females, 
which had placed their eggs in the spiral part of the shell. 
One female, that had deposited all her eggs, withdrew com- 
pletely within the shell, as in fig. 3; her body on one side had 
* The rudiment of the bone, which occurs in the polypus, (as has been obseryed by 
Cuvier) is not to be found in the Ocythoé. 
