very one who has been working within a special, circum- 

 scribed field of systematic biology, must no doubt have often 

 felt the want of lists of all genera known within the range 

 of his research, giving at least the most necessary references, 

 as to the scientific papers where the authors first described their 

 new genera. Where the excellent and trustworthy works of 

 Beonn and L- Agassiz cease, the naturalist is left to his own 

 resources. Even the latest published Xomenclators, as those 

 of Marschall and ScunnEE do not by far include all genera 

 published since the works of the first mentioned authors were 

 printed. It is evident that the nearest approach to complete- 

 ness can only be attained througb the exertions of specialists 

 each for the order he has cultivated. The present index which 

 is now offered to fellow workers, enumerates genera, created 

 since 1758 when the etill prevalent binominal system was 'in- 

 troduced by LinNjEUS in the Tentli Edition of his »Systema 

 Natur£e». It has however not been considered worth the while 

 to swell this list with names and references of some thirty so 

 called new genera formed by LunwiG ^) and contrary to all 

 adopted rules, at the expense of old, and well established 

 genera. To give a single instance amongst numerous others 

 he has discarded the well known and generally adopted name 

 Halvsites and tht>ught fit to replace it with such a scsquipe- 

 ialian name as Piychopldceocyathus without the least conceivable 



foundation. 



With Egyptian types (Acantliophylluni) such names are 



printed, which belong to well established genera; the names 



of mere synonymous genera are printed in italics {Acan- 



tJiodes) and uncertain, dubious or not acceptable genera are 



printed in spaced letters (Archaiocyathus)- Next the name 



of the author the year of publication follows and the name 



i^ 



^) >Corallen aus palaolitischen ForniatioD<?ns in ^Palfeontographica vol. 

 14. 'l865-GC.> 



