NEMERTEANS 239 



others on each side of the rhynchocoel. They do not approach the brain. The proboscis 

 is attached about the half length of the body. The rhynchocoel extends the whole length . 

 The accessory armature consists of two reservoirs each with five or six stylets. There are 

 eleven nerve strands in the proboscis. 



Two blood vessels, one on each side of the rhynchodaeum, form a loop in the head. 

 They are lost at the ganglia, but reappear as two lateral vessels above the nerves. A dorsal 

 vessel above the gut is connected by a branch on each side with the lateral. 



The excretory tubules are packed close behind the ganglia. From them single ducts 

 on each side pass back above the lateral nerves and vessels and turn outwards some dis- 

 tance behind the brain. 



The dorsal commissure is longer and thinner than the ventral. The ventral ganglia, 

 becoming the lateral nerves, shift very gradually outwards. The dorsal ganglia taper 

 posteriorly and the cerebral canals pass in beneath them and widen into the cerebral 

 organs which are thus wedged between dorsal and ventral ganglia behind the ventral 

 commissure. The organs swell as the dorsal ganglia diminish in size, and when the latter 

 join them they are somewhat flattened bodies larger in cross-section than the lateral 

 nerves at the same point. They are rounded posteriorly, but extend back some distance 

 from the point of fusion with the fibres of the dorsal ganglia. 



There seems little doubt about this identification. Graphic reconstruction of the head 

 of the specimen sectioned gives a plan of the vascular and nervous systems identical 

 with that figured by Mcintosh (1873), and in all particulars the description corresponds 

 with those of other workers. 



Another specimen (N 127) was collected by Mr E. R. Gunther from a sponge brought 

 to the surface from 292-402 m. by a trawler from Cape Town on July 8, 1927. This was 

 noted in life as "flesh-coloured". 



The preserved specimen was 27 mm. in length, 7 mm. broad and 3-5 mm. thick. 

 The body was stout and flattened from above down. It was sectioned and identified 

 with this species. 



Genus Zygonemertes, Montgomery 



Zygonemertes capensis, n.sp. (Plate XV, figs. 3, 6, 12; Figs. 13-16). 



Variations in colour and form were responsible for five descriptions and sketches of 

 this worm (N 26, N 29, N 33, N 38, N 39). These five have been reduced to three 

 fairly constant colour variations which are described and figured separately. 



(1) Green form. Twenty-seven specimens were taken from attached and washed-up 

 kelp roots inside and outside the south arm of the Bay. The largest worms were 

 80 mm. long, 1-5-2-0 mm. in breadth; the smallest 14 mm. long, 0-5 mm. in breadth. 



In life the body is slightly flattened and soft. The head is flat, broader than the suc- 

 ceeding part of the body and somewhat diamond-shaped in outline from above. The 

 snout is blunt. The tail is pointed and a little bulbous. Neither mouth nor cephalic 

 slits can be seen. The colour on the back is green, greyish green, or light brown tinged 



