VERANY AND VOGT ON THE HECTOCOTYLI. 119 



Article V. 



Memoir upon the Hectocotyli and the Males of certain Cephalo- 

 pods. By MM. J. B. Verany and C. Vogt. 



[^Annates des Sciences Naturelles, t. xvii. No. 3, 1852.] 



1 HE manner in which the fecundation of some Cephalopods, 

 especially of the Argonaut and of the Tremoctopods, whose 

 females only have been known up to the present time, occurs, is a 

 zoological question of the highest interest. The very recent re- 

 searches of MM. Kolliker and Siebold having called the atten- 

 tion of naturalists to this point, we have neglected no opportunity 

 of procuring fresh and living animals, by the study of which we 

 hoped to arrive at a definite solution of the problem. We ven- 

 ture to think that our investigations have been rewarded by 

 complete success, at least for one species. 



The memoir which we now lay before the Academy relates 

 principally to the Tremoctopus Carena (Verany) and the Hecto- 

 cotylus which is derived from it. We shall give, first, a historical 

 summary of the labours of our predecessors ; then the zoological 

 description of the species which occupies us, and which was to 

 a great extent unknown up to the present time ; lastly, we shall 

 conclude our work by a detailed study of the reproductive 

 organs. 



Historical Introduction. 



M. Delle Chiaje, at Naples, described and figured in the year 

 1825* a little animal found by him parasitic upon an Argonaut, 

 to which he gave the name of Trichocephalus acetahularis. 

 This animal, when once detached from the Octopus, to which 

 it was adherent, swam and crept at the bottom of the water with 

 uneasy movements. It appeared full of Hfe for many hours. 

 M. Delle Chiaje did not doubt that this parasite was one of the 

 Helminthic worms, and placed it in the genus Trichocephalus of 



* Memorie sulla Storia e Notomta degli Animali senxa vertehre del regno 

 di Napoli; di Stefano Delle Chiaje. 



