1903] On the Nemerteans of Norway. 9 



in life bright orange vermilion. Head lighter and more pink. 

 A Yshaped light band was visible just behind the head, 

 and a transverse band about the end of the oesophageal 

 region. Botn bands were faint. (Pl. I, fig. 10 a). After 

 preservation the worm did not shew the characteristic dark 

 area found in the anterior intestinal region of C. polymorpha 

 under similar conditions. Otherwise this species shews con- 

 siderable resemblance to C. polymorpha as regards its ex- 

 ternal features. 

 Body wall. Botn the epithelium and the basement membrane 

 on which it rests are very thick. The circular muscle layer 

 is muen thinner than the basement membrane. The longitu- 

 dinal muscle layer is well developed and is of about the 

 same thickness as the epithelium. The relative development 

 of the various layers differs in the oesophageal and intestinal 

 regions as the following figures shew: — 





Circular 



basement 



longitudinal 



epithe- 





muscles 



membrane 



muscles 



lium 



Oesophageal . . 



1 



3 



7 



7 



Intestinal 



1 



2 



4 



4 



The epithelium in the oesophageal region contains a 

 deeper layer of composite glands. Peculiar unicellular glands 

 with a great affinity for picric acid are found in the middle 

 of the oesophageal region. The area containing these cells 

 comprises about one half of the oesophageal region, star- 

 ting soon after the mouth and ending shortly after the level 

 where the excretory tubules are first found. In the intesti- 

 nal region these cells are absent, as also is the deep layer of 

 composite glands found in the oesophageal region. 



The inner circular musculature is well developed. No 

 crosses occur between it and the outer circular layer. Be- 

 tween the oesophagus and the proboscis sheath is a layer of 

 longitudinal fibrils. 



The alimentary canal the proboscis, and its sheath present no features 

 calling for remark. 



The vascular system in the head shews a large cephalic lacuna 

 somewhat broken up by muscular strands running through it 

 dorso-ventrally. 



