630 



GERARDA STIASNY-WIJNHOFP 



with Bdellomorpha (Verrill) and Hoplonemertini (Hubrecht) 

 (Text-fig. 1, c). 



Class Nemertini. 



Sub-class 1. Anopla. 



Sub-class 2. Enopla. 



Order 1. Order 2. 



Palaeonemertini. Heteroneiuertini. 



Order 3. 



Bdellomorpha. 



Order 4. 



Hoplonemertini. 



The sub-class Enopla (Text-fig. 1, c) shows a tendency to have 

 the digestive system and the proboscidian apparatus opening 

 to the exterior by one aperture. In the Anopla both openings 



I ' I ' I ' ' ' ' I I r 



Text-fig. 2. 



cLrtcorrun. 

 rhynch 



v.n comm. 



Schematic longitudinal section of an unarmed Nemertean after 

 Burger (6, PI. xxi, fig. 1, Cerebratulus marginatus). 



are always widely separated, as shown in Text-fig. 2 ; in the 

 Enopla the common aperture is obtained in different ways. 

 The Bdellomorpha, containing the parasitic genus Malacobdella, 

 which Burger included in his Metanemertini, though it lacks 

 an armed proboscis and shows great differences in the structure 

 of almost every organ, has its proboscis inserted in the wall of 

 the stomodaeum (Text-fig. 3). In the Hoplonemertea the same 

 result, one common mouth, is developed in two other ways, as 

 will be shown afterwards. As Biirger's Metanemertini are 

 only a newer name for Hoplonemertini his subdivision of this 

 order into Pro- and Holo-rhynchocoelomia might be followed 

 in our system as well. The main difference between these 



