60 



ZOOLOGISCHE MEDEDEELINGEN — DEEL V. 



anterior lip, that has about the same length as the ventral ligule. The 

 ventral cirrus only reaches to half the length of the ventral ligule. On 

 the dorsum of the 14 th parapodium, behind the place of insertion of 

 the dorsal cirrus, a small, conical tubercle becomes visible, that in the 

 succeeding segments grows larger and acquires a digitiform shape ; in the 

 posterior body-region this appendage becomes tongue shaped, whereas also 

 the dorsal ligule grows broader and acquires a foliaceous appearance. The 

 parapodial appendage is rich in blood-vessels and presumably will have 

 the function of a gill. The dorsal bristle-fascicle consists of homogomph, 

 setigerous setae; the ventral one in its superior part contains also homo- 

 gomph setigerous and some heterogomph, falcigerous bristles, whereas in 

 its inferior part there occur heterogomph, falcigerous setae, with a slender, 

 ciliated terminal piece and some heterogomph setigerous bristles. 



Nereis (Perinereis) rumphii n. sp. 



Siboga-expedition, Stat. 272. Dobo, Aroe-islands. Reef-exploration. 1 

 specimen. 



Off the south-coast of East-Flores. Dr. van der Sande, 14 Jan. 1909. 

 1 specimen. 



Road of Koepang, Timor. Dr. van der Sande, 22 Jan. 1909. 1 specimen. 

 Amboina. Dr. L. F. de Beaufort, March 1910. 28 specimens. 



At the above-named localities several Ne- 

 reis-specimens were collected, which, though 

 closely allied to Ner. mietodonta Mrz. , ), in 

 my opinion can not be identified with this 

 species 2 ). The worms are in a different stade 

 of sexual maturity, among those from Am- 

 boina 15 being atocous, whereas 11 are epito- 

 cous females and 2 are males, however with- 

 out having the setae of the atocous phase 

 replaced by swimming bristles, as well is the 

 case with the specimens from Dobo and Flores 

 and Koepang. The atocous specimens attain 

 a length of 110 mm., whereas the 9 mea- 

 sure about 85 and the <ƒ ones on ty 64 mm. in length. The body is 

 nearly discoloured; only the papilliform, distal piece of the palps is 

 densely covered with small, oval, white spots and in the median body- 

 region a patch of dark pigment appears on the dorsum of the parapodia, 



1) Südjapan. Aoneliden, I, 1879, p. 10, PI. II, fig. 2. Izuka, Errant. Polychaeta of Japan p. 148, 

 pi. XVI, iigs. 1-6. 



2) Presumably it has been done by Pishly, who mentions Ner. mietodonta from Ternate, however 

 without any remark (Polych. von Ternate, Abh. Seuekenb. Naturf.Gesellschaft, Vol. XXV, 1903,p.ll3). 



