402 APPENDIX, No. II. 



of the sac, iiamediately above the branchiae, 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 loligo and sepia, 

 does not exist in the, polypus* 



Although the superior arms are stated to perform such diife- 

 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 ocythoe 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. 



OCYTHOF. 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. PI. 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 M^as 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 pohjpus, (as has been observed by 

 Cpvier) is not to be found in the Ocythoe. 



