ON SOME SOUTH PACIFIC NEMERTINES COLLECTED BY DE, WILLEY. 573 



The excretory system reaches anteriorly almost as far as the hind end of the brain. 

 Posteriorly it stretches nearly as far as the commencement of the gonads. There is a 

 single pore on each side which occupies a very forward position at the level of the 

 conunencement of the mid-gut and in front of the hinder end of the cerebral organ. 



The generative organs were nearly ripe. The individual is a ?. The ovaries are 

 large and crescentic in shape, and each with a single opening (Fig. 20). They alternate 

 regularly with the intestinal pouches and rhynchocoelom diverticula from which they are 

 separated by muscle strands. 



Thus it will be seen that this species of Drepanophorus is well marked from 

 other species of the genus, being characterised by the unusually large head furrows, 

 the small number of the eyes, the large size of the rhynchocoelom diverticula, and by 

 the number of the proboscis nerves. I have much pleasure in associating it with 

 Dr Willey's name, more especially since he examined the animal carefully when alive 

 and made the interesting observation that "when just taken it frecpiently and rapidly 

 alternately extruded and retracted its probo.scis much in the same way that Ctenoplana 

 uses its tentacles." 



3. Drepanophorus lifuensis, n. sp. PI. LIX. Figs. 21 — 27. 



The single specimen of this species which was procured at Lifu is a flattened form 

 measuring 4 mm. in width, 1'5 mm. in depth, and 4'5 cm. in length. A coloured sketch 

 was made b}' Dr Willey of the live animal from which it appears that the dorsal 

 surface was of a bright palish red, whilst the ventral was quite white. The anterior 

 end was whitish and on it the eyes appeared as four dark blue longitudinal lines. The 

 appearance of the preserved animal agrees closely with that given by Burger for 

 D. Iritus ((1) p. 27). The animal possessed a small " tail," coloured like the rest of the 

 body (Fig. 26, c). Sections made through it shewed that the anus opened at its 

 extremity. There was, however, no anal commissure, the nerve cords ending blindly 

 and somewhat abruptly, and I am inclined to believe that this " tail " has its origin 

 in some regeneration process following upon an injury to the posterior end of the 

 w'orm. 



Another point of interest with regard to the external features of the animal lay 

 in the fact that the epidermis, with the exception of a few small isolated patches 

 here and there, had almost entirely disappeared, the basement membrane being left 

 exposed to the external woi-ld. Coupled with this was the presence of a small 

 insect larva a few millimetres in length, labelled by Dr Willey as parasitic on this 

 worm. One is tempted to draw the conclusion that this little creature obtained its 

 nourishment by browsing upon the epidermis of the Nemertine, in which case it would, 

 with the exception of latoshia gigas, be the only external parasite recorded for the 

 group. 



With regard to internal features the species shews a great resemblance to D. 

 lutus. 



The head glands (" Kopfdriisen ") are short and feebly developed. The mouth is 

 slit-like and ventral in position, and the proboscis pore is at its anterior end. The 



70—2 



