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GERARDA STIASNY-WIJNHOFF 



founded. The following schema gives the synonyms in the 

 different systems. 



The combination of Burger's three other orders in the 

 Dimyaria was not well founded. Burger meant them to be 

 two stages in the development of the third, the Metanemerteans 

 or Hoplonemertini ; the Protonemertini with their epithelial 

 nervous system (Text-fig. 1, a) being the most primitive ones. 

 Carinoma and Cephalothrix, the Mesonemertini, give the 

 development that leads to the central position of this system 

 in the body parenchyma (Text-fig. 1, c). Now Bergendal, 

 in his treatise on Carinoma armandi (2), made it clear 

 that this genus is closely related to Carinella and the Hetero- 

 nemerteans (Text-fig. 1, h), and has no affinity at all to Cephalo- 

 thrix nor to the armed Nemerteans. In another Swedish 

 article he shows (1) that Biirger's order Mesonemertini is 

 quite unnatural, and that both genera Cephalothrix and 

 Carinoma are true Protonemertini; so Hubrecht 's order 

 Palaeonemertini ought to be restored. A study on Cephalo- 

 thrix taught me (16) that this genus is not nearer related to 

 the armed Nemerteans than to the unarmed, and so we get 

 instead of Proto- and Meso-nemertini the old order of Palaeo- 

 nemertini, nearly related to the Heteronemertini and without 

 any special relation to these groups the armed Nemerteans. 

 In 1912 (17) I proposed to return to the old division of Max 

 Schultze. The class Nemertini is subdivided into two 

 sub-classes : Anopla and Enopla. Each sub-class contains 

 two orders : the Anopla with Palaeonemertini (Hubrecht) and 

 Heteronemertini (Biirger), of which diagnoses were given and 

 schemes are given here in Text-fig. 1, a and h ; and the Enopla 



