NEMERTEANS 



259 



end of the stomach is about twice as thick as the basement layer which is considerably 

 thicker than the circular muscle layer. The longitudinal 

 muscles are well developed. 



There appears to be no distinction between oeso- 

 phagus and stomach. A large folded tube passes through 

 the region of the brain and opens by a frilled mouth 

 under the proboscis pore. The tube enlarges slightly 

 posteriorly. Branches of the anterior caecum reach the 

 brain. 



The proboscis possesses thirteen nerves and is stout 

 and muscular. There is no dorsal strand in the lateral 

 nerves. The cerebral organs are small and only just reach 

 the brain. Their short canals open ventro-laterally. There 

 are about fifteen eyespots on each side. The specimen 

 was a male with immature testes. 



I have separated this worm from the other Amphi- 

 porids on the nerves in the proboscis and the position and size of the cerebral organs. 



Fig. 32. Amphiporus inexpectatus , 

 n.sp. Transverse section at the 

 extreme tip of the head with the 

 protruded proboscis, p. hg, head 

 glands. 



Amphiporus lecointei, Burger, 1904 a (Plate XVI, fig. 9; Figs. 33-35, 3 6B )- 



This species was taken at the following stations : 



St. 27. 15. iii. 26. DL, nom. 1 (N 114). 



St. 140. 23. xii. 26. OTL, 122-136 m. 4 (N 45). 



St. 156. 20. i. 27. DLH, 200-236 m. 2. 



St. 158. 21. i. 27. DLH, 401 m. 2. 



St. 159. 21. i. 27. DLH, 160 m. 4. 



St. 195. 30. iii. 27. OTM, 391 m. 2. 



St. WS 25. 17. xii. 26. BTS, 18-27 m - 2 ( N I20 )- 



St. WS 93. 9. iv. 27. N 7-T, 133-130 m. 6 (N 125). 



St. MS 71. 9. iii. 26. NCS-T, 1 10-60 m. 1 (N 115). 



One specimen (N 45) was examined and sketched in life and afterwards sectioned. 

 This, though similar in many respects to A. michaelseni, Burger, has been separated 

 from it by reason of the cerebral organs, armature and the number of nerves in the pro- 

 boscis. It has been identified with A. lecointei, Burger, on the shape, head glands, brain 

 and cerebral organs. Much should have been added to make the original description 

 adequate, for there is great similarity in the anatomy of the closely related species 

 lecointei, gerlachei, falklandicus and marioni. 



The length was 20 mm. and breadth 2-3 mm. A specimen sketched by Mr D. D. 

 John at St. 156 was 23 mm. long. 



Form and colour in life. The size and shape is remarkably uniform. The body is stout, 

 almost circular in cross-section, bluntly pointed at the head and tapering to the tad. The 

 head is marked off from the body by a transverse groove deep ventrally and incomplete 

 dorsally. At each side the groove takes the shape of a backwardly directed V, and from 



