I]. Some Observations upon the Structure of two new Species of Hectocotyle, 
parasitic upon Tremoctopus violaceus, D. Ch., and Argonauta Argo, Linn.; 
with an Exposition of the Hypothesis that these Hectocotyle are the Males 
of the Cephalopoda upon which they are found. By A. KórrikEn, Pro- 
fessor of Physiology and Comparative Anatomy in the University of Zurich. 
Communicated by Ropert Brown, Esq., V.P.L.S. &c. &c. 
Read April 15th and May 6th, 1845. 
x. 
WHILST visiting Messina and Naples during the summer of 1842, I found 
two worms resembling the Hectocotyle Octopodis, described by Cuvier as found 
upon the Octopus granulosus, Lam. ; the one upon the Tremoctopus violaceus, 
Delle Chiaje (Octopus velifer, Fér.), the other upon the Argonauta Argo, L. At 
first sight I took them for epizootic worms, to which, from their white colour 
and numerous suckers, they bore a great resemblance; but when I examined 
them more accurately, I met with so many peculiarities, a few of which I will 
here mention, namely the existence of a heart, arteries and veins, branchiz, and 
coloured contractile pigment-cells, that at length I was compelled to abandon 
that idea. Proceeding with my examinations, I soon found that the animals 
were all males; and remembering that that sex of the Argonauta and Tremoc- 
fopus was not as yet known, I supposed that I had discovered the males of 
those Cephalopoda. I must confess that at first I did not place much reliance 
upon this conjecture, for the great dissimilarity between the supposed sexes 
surprised me so much that I scarcely dared to believe it to be well-founded. 
However, as I proceeded further with my researches, I found more and more 
to strengthen my supposition, so that finally I was led to regard it as very 
probable. But before proceeding to submit the arguments on which [ formed 
my opinion, I propose to give a slight sketch of my anatomical researches 
with respect to the above-mentioned animals. 
VOL. XX. Cc 
