iU 



ZOOLOGISCHE MEDEDEELINGEN — DEEL IV. 



larger. In the oral region there occurs on area V a transverse group of 

 of 12 to 14 small, distant, obtuse-conical paragnaths ; group YI consists 

 of 3 to 5 paragnaths, but is not distinctly separated from group VIII, 

 that forms with group VII a complete belt of small paragnaths, the 

 larger ones being situated anteriorly. 



In the anterior region of the body the parapodia are provided with 

 an obtuse conical, dorsal ligule, about as long as the notopodial lobe; 

 the latter one has a conical, anterior lip, which reaches to about half 

 the length of the ligule. The neuropodium with its conical posterior lip 

 extends a little beyond the notopodial lobe; it has an obtuse conical, 

 anterior lip, half as long as the posterior one and a ventral ligule of 

 the same length. The dorsal cirrus extends nearly to the extremity of 

 the dorsal ligule, whereas the ventral cirrus is much shorter and only 

 reaches to half the length of the ventral ligule. In the female the ante- 

 rior 5 parapodia have the dorsal cirrus enlarged in its ventral part; in 

 the male this occurs in the anterior 7 parapodia. The notopodial fascicle 

 only consists of homogomph, setigerous bristles ; the neuropodial one in 

 its dorsal part contains homogomph setigerous setae and some heterogomph 

 falcate ones, whereas its ventral part consists of heterogomph setigerous 

 and falcigerous bristles. The terminal piece of the falcate bristles is 

 elongated, faintly bent and terminates in an obtuse apex. 



The epitocous change of the parapodia much resembles that of other 

 Nerei'dae and commences in the male with the 18 th feet, in the female 



with the 22 d ones. At the base of the 

 dorsal cirrus a small, comb-like lamella 

 appears, whereas the cirrus itself in the 

 male is provided with 7 to 8 papillae 

 along the ventral border; the dorsal 

 ligule has a pointed, conical shape and 

 the dorsal lobe obtained the shape of a 

 ploughshare. At the ventral lobe a 

 rather large lamella, with a crenulated 

 margin, has been developed. The ven- 

 tral ligule is pointed, tongue-shaped and 

 the base of the ventral cirrus bears 

 inferiorly a fan-like lamella and supe- 

 riorly a club-shaped appendage with an 

 obtuse conical lobe on its dorsal border. 

 In the male specimen the parapodia of the posterior segments show the 

 last vestiges of the Heteroner eis- form, by the presence of small, papuli- 

 ferous lobes at the base of the ventral cirrus ; the swimming bristles have 



Nereis nouhnysi no v. sp. 

 Epitocous parapodium. 



