1903] On the Nemerteans of Norway. 31 



unable in the single specimen of this organ to clistinguish any 

 reserve stylets. Possibly they are normally absent, as it 

 seems improbable that they shonld have been dissolved out 

 whilst the central stylet was left intact. 



The proboscis sheath extends throughout the whole length 

 of the body. 



The alimentary canal shews no features of special interest. The 

 stomodaeum and rhynchodaeum are quite separate to the com- 

 mon pore. The blind gut does not reach forwards- nearly to 

 the brain. 



Vascular system is built up on the usual metan emertean plan. In 

 the anterior oesophageal region the lateral vessels give off a 

 few small dorsal diverticula, in close contact with wMch, as 

 with the lateral vessels themselves, the excretory tubules 

 come to lie. 



The excretory system is found shortly after the hind end of the 

 brain. It extends along the front half of the oesophagus, 

 and its tubules disappear soon after front limit of the blind 

 gut. A single ventral pore occurs on either side at about 

 the middle of the system. 



Gonads between the intestinal diverticula arranged regularly. Each 

 gonad has a dorsolateral op ening. 



Xervous system. For the size of the worm the brain is very small. 

 The dorsal ganglion is but slightly larger than the ventral. 

 The cerebral organ is well developed and lies beside the 

 brain, being closely opposed to the out er surface of the dor- 

 sal ganglion with which it is coextensive in length. The cere- 

 bral canals open ventrolaterally and just in front of the an- 

 terior limit of the brain. 'The head glands are small. They 

 reach about Va wa Y fr° m the tip of the snout and the brain. 

 The eyes are large and numerous, and the most posterior of 

 them are found just over the anterior part of the brain. 



21. Amphiporus thompsoni (Punxett, 1901). 



Two specimens of this characteristically marked species, one 

 each from: — 



a) Porsangerfjord (Finmark) from 200 metres on a bottom of 

 mud and rock. Temperature 0.2° C. 



