ON SOME SOUTH PACIFIC XEMERTIXES COLLECTED BY UK WILLEY. 571 



to the exterior (Figs. 2, 7, and 9). There is no direct communication between 

 any part of the vascular and excretory sj'Stems. The excretory system is relatively 

 further behind the brain than in any other Nemertine. 



The generative organs were not quite ripe. They formed a continuous band on 

 each side of the body. Doubtless thej^ represented a number of glands closely apposed 

 and each opening by its peculiar orifice. These however were not yet distinctly formed, 

 though traces of them could be made out here and there (Fig. S, ov.). 



The brain is simple in structure and has the appearance of the nerve cords being 

 much swollen in this region, since the dorsal ganglion is not sharply separated off 

 from the ventral. There are two dorsal ;in(l two ventral commissures, the posterior 

 dorsal and the anterior ventral lying at the same level (Fig.s. 2 and 4). From 

 the posterior ventral commissui'e are given off the two strong oesophageal nerves. 



There is a small median dorsal nerve extending backwards just beneath the 

 basement membrane. In front of the brain there is a well-marked nervous layer 

 just beneath the basement membrane (Figs. 3 and 11, n.l.). There are no neuro- 

 chords. 



There are no special sense organs, eyes and frontal organ being absent. More- 

 over there is no lateral sense organ such as has been described by Burger for 

 Carinella, in the neighbourhood of the excretory pore. 



Carinesta orientalis is one of the few Nemertines without cerebral slits, a peculiarity 

 shared with CarinovHO and Malacohdella alone. 



jVETA nemer tixi. 



'1. Drepiinophorus willeyanus, n. sp. PL LVIII. Figs. 12 — 17 antl LIX. 18 — 20. 



A single specimen was found by Dr Willey in Blanche Bay. Its dimensions when 

 preserved were 7'5 cm. in length and 2'3 mm. in breadth. The posterior end was 

 sharply pointed. In life the worm was of a lightish brown dorsal ly whilst the 

 ventral surface was dirty white. The head furrows were very conspicuous in 

 the living animal as a series of deep chocolate brown stripes on either side dorso- 

 laterally (Fig. 12). They are more strongly developed than in any other .species of 

 Drepanophonis, their condition being most nearly approached by that obtaining in 

 B. spectabilis. The eyes were easily seen in the living animal and were disposed in 

 the arrangement characteristic of the genus. Uorsally and laterally there was a row 

 of three eyes on each side whilst ventro-laterally and rather more anteriorly was a 

 row of five on each side (Figs. 12 and 13), thus making a total of sixteen eyes. 

 All the other known species of Drepanophorus possess at least thirty eyes, and this 

 character has been taken by Burger as characteristic of the genus (Biirger (4) 

 p. I(i8), so that in this respect D. willeyanus differs markedly ho\n its relatives. 



Tlie basement membrane, as is usual in this genus, is well marked, being nearly 

 as thick as the epidermis (Figs. 13 and 18, b.m.). The body parenchyma in which 



' Biirger states that there are no cerebral slits in Cephalothrix and makes this a character of the genus. 

 Joubin however figures them for Cephalothrix linearis ((8) PI. XXVI. tig. 24). 



w. V. 76 



