804 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



were beginning to take on the cliaracters of an arthropod ; the Nauplius 

 would then be an altered larval form of the annelid phylum ; Claus 

 has already directed attention to the likeness between a" Nauplius and 

 a trochoph ore-larva provided with a trunk-segment, while Dohrn 

 has completely given up the old " Nauplius-theory." Hatschek has 

 rightly pointed out that the larv^ of arthropods must be referred to 

 the larvae of annelids ; though the Nauplius is unsegmented externally 

 its body has the value of metameres. 



Prof. Claus' views on the interrelationships of the Malacostraca 

 are best shown by his own table : — 



Nebalia Amphipoda Isopoda Tanaida Oumacea Schizopoda Decapoda Stomatopoda 



Promalacostraca 



Protostraca 



The Knes of descent of the groups of the Entomostraca are thus 

 indicated : 



Ostracoda 



Phyllopoda Argulidse Copepoda Cirriped: 



Protostraca 



