SPECIAL PART 



THE first Echinoderm larvae described were designated, more or less 

 consistently, by binominal names — Bipinnaria asterigera Sars, 

 Pluleus paradoxus Joh. Miiller, Pluteus bimaculatus Job. Miiller. — It 

 is true, they were partly not recognized as Echinoderm larvae; but this 

 does not alter the fact that these larvae got binominal names. In the 

 author's work on the Echinoderm larvae of the Plankton Expedition this 

 principle was carried through consistently for all Echinoderm larvae 

 known till then, in view of the necessity of having the different larval 

 forms designated in such a way that we may understand without too 

 much trouble what we are speaking of. This request is met in a satisfactory 

 way by the binominal nomenclature, but not by such designations as 

 "Auricularia mit Kugeln", "Bipinnaria aus Helsingor" or the like, used 

 so often in the elder litterature (Joh. Miiller, Metschnikoff). For 

 larvae of known origin no special larval name was created, which was, 

 of course, unnecessary. This way of naming the larvae has been generally 

 adopted by the few authors who have since then described Echinoderm 

 larvae of unknown parentage (Ma cB ride, Gem mi 11). 



In the present work the same method is also adopted, but modified 

 to some extent. On account of the great number of new larval forms 

 of unknown origin described here, especially of Ophiurids, it was felt as 

 a difficulty that there would result a great number of 'specific" names, 

 from which nothing could be seen as to their mutual interrelation. The 

 object with describing especially the many different Ophiopluteus species 

 being mainly to show that also among the Ophiurid larv« there are 

 several well characterized groups, corresponding to what is found among 

 the other Echinoderm larvae, notably among the Echinoid larvae, it was 

 found preferable to give only each type a binominal name, and then to 

 designate the different species under that type as species a, b, c etc. 

 A consequence of this is then further that it is incorrect to designate 

 such new larval type as "nova species"; it is then designated as "nova 



