1903] On the Nemerteans of Norway. 23 



both dorsal and ventral surface. Lateral edges of body white. 

 No candicle was present on the specimen obtained but, judging 

 from its internal anatomy, this was probably once present 

 and broken off before capture. 



Body wall. The epithelium is crowded with unicellular glands 

 (Pl. I, fig. 8) some of which stain deeply with carmine 

 whilst others ramain unaffected. Under the very fine base- 

 ment membrane is a delicate layer of circular muscle fibrils. 

 The cutis glands are much attenuated and fibres from the 

 outer longitudinal muscle layers reach up amongst them. In 

 the oesophageal region the outer longitudinal muscle layer is 

 about double the thickness of the circular layer whilst this 

 again is twice as thick as the inner longitudinal layer. 



The proboscis contains two muscle layers. The muscle crosses are 

 well developed. The proboscis sheath extends to the poste- 

 rior end. 



Alimentary canal. The mouth is found rather far forwards at the 

 level of the cerebral organ. A small anterior portion of the 

 intestine is unprovided with pouches. 



The vascular system presents an unbroken cephalic lacuna. The 

 oesophageal network is not well developed. Immediately 

 after the termination of the excretory system the lateral 

 lacunae become transformed into the lateral vessels. The 

 median dorsal vessel leaves the proboscis sheath behind the 

 termination of the excretory system, about half way between 

 this and the intestine (Pl. II. fig. 18). 



The excretory system commences soon after the posterior limit of 

 the mouth and extends only as far as the middle of the 

 oesophagus. Its tubules are found both above and below the 

 level of the nervous side stems. At the posterior end of 

 the system a single duct is found on either side. 



Nervous system. The dorsal ganglion is not much larger than 

 the ventral. Each head slit is wide and has a depth of 

 about Vs of the lateral diameter of the head in the brain 

 region. The head slits reach almost to the brain. The cilia- 

 ted canal is given off just before the level where the cerebral 

 organ commences. At this level the head slits terminale 

 having previously become somewhat shallow. 



Eyes absent. The head glands are scanty. They extend 

 farther back dorsally than ventrally. A well-marked frontal 

 organ is present. 



