We wish to thank Sir Edwin Rav Lankestek, Profs. E. Perkier, F. E. Schulze, C. Chun, 

 A. Agassiz and Axt. Dohrn for their valued permission to carry out such examination and 

 Messrs. Kirkpatrick, Joubin, Eisig, INIaver and Lo Bianco for their personal assistance. 



All this has made us very diffident whenever the cjuestion of instituting new species or 

 genera arose. Among the Physonecta we have distinguished four groups which may possibly 

 contain a certain number of new .species, .sufficiently distinct the one from the other, but which 

 we refrain from introducing into science under separate specific names so long as they have 

 not been examined in the living state. We have not adopted the same plan for all the 4000 

 specimens of which the Siboga collection consists, although we must admit that about 600 of 

 these are too damaged or too insufficiently preserved to allow of even an attempt at specific 

 determination, many Calycophorids being moreover represented only by loose special nectophores, 

 bracts, gonocalyces or inferior nectophores. In some cases we must recognize that our descriptions 

 can be no more than provisional. 



On the other hand we feel justified in looking upon our new genera Claiisophyes^ Clutni- 

 phycs, Diphyabyla and Archa7igelopsis as more definitely established and have no doubt that 

 it will not be difficult to recognize them among the harvest that future expeditions may garner. 



Besides these genera we have described 1 8 new species, some of which — more especially 

 the eleven new Calycophorids — are very much in want of confirmatory observations. 



One new subfamily has presented itself to us (Dipkyadylmae)-^ to one family {Bathy- 

 physidae) we have secured its definite right of existence in the system. Finally we feel justified 

 in proposing the total suppression of the order of Auroneclae (Haeckel) and the arrangement 

 of the genera belonging to it in the family of the Angelidae, which was introduced by Fewkes 

 in 1S84. This is undoubtedl)- of some importance also from a more general point of view. 



Finally we wish to express our thanks to Prof Hubrecht for the hospitality afforded to 

 us in his laboratory during the four years that we have been occupied with this collection and 

 for his kind help and advice on so many occasions. 



As to Prof. Weber, we hope that he will not regret having entrusted the working 

 up of the SipJionophora of his eminently fruitful expedition to our inexperienced hands. The 

 responsibility he has laid upon us has been a constant stimulus, the confidence shown to us 

 an invaluable source of energy for the completion of an arduous but inspiring task. 



