19 



or less comploli'ly. ol' no loss lliaii .").') dillVriMil lorms of I'",cliiiio(li"rins, 

 lilt' (k'vc'l()|)iiu'iil of wliich was totally uiikiiown till now. 'I'Ik' present 

 c'onliibulioii ac('oi(tiiii»ly represents a veiy eonsitlerable addition to our 

 knowledge of the developnienl and llu' larval forms of Echinoderrns and 

 — combined with onr previous knowledge forms a reasonable founda- 

 tion for a discussion of the problem that was the main object of these 

 researches: the intenclation between the larva; and the adults in regard 

 to a natural classification. .Mso the comparative study of pelagic larva* 

 of uid^nown |)arentage, especially of the ()|)hiurid larva', yields valuable 

 support for the conclusions to be drawn. Of course, very much more 

 needs to be done. Ihe investigations here recorded may only lie regarded 

 as an introduction. Still, enough is done already to give us a glimpse 

 of the end; it is evident that the way here entered upon is the light way, 

 which will lead to the desired results. I hope to be able in the future 

 to carry these researches further towards a definite solution of the problem. 



3* 



