NO. 1 HARTMAN : GONIADIDAE, GLYCERIDAE, NEPHTYIDAE 115 



The first parapodia are directed forward to lie at the sides of the 

 prostomium. Notopodial and neuropodial rami are about equal in size 

 but the notopodial cirrus is a mere vestige whereas the ventral cirrus is 

 large, thick, conical, resembling the ventral prostomial antenna or the 

 ventral cirrus of the second parapodium. Setae of the first segment are 

 directed forward; the preacicular series are fully developed; the post- 

 acicular series few, weak and delicate. Those of the notopodium are 

 slightly longer and more numerous than those of the neuropodium. By 

 the second segment, the postacicular fascicle has attained an importance 

 nearly equalling that of the preacicular series. The notopodial parts are 

 more fully developed and the rami are widely separated. 



The notopodial cirrus is acutely conical from about segment 3; 

 farther back it comes to be increasingly longer, is directed laterally as a 

 slender, tapering filament and extends far beyond the other parapodial 

 lobes. There is no erect or prolonged lobe on the superior edge of the 

 neuropodium. In a typical parapodium (figs. 1 and 2) postsetal lobes 

 of both rami are foliaceous and consist of broad lobes, the upper one 

 slightly serrated at the edge, the lower one similar or entire. The 

 acicular lobe is acutely conical, distally prolonged so as to extend be- 

 yond the other parapodial lobes; the aciculum may be more or less 

 withdrawn into the fleshy lobe or slightly projecting. Posterior acicular 

 lobes are slenderer and more prolonged than those in front, but all may 

 be described as conical. 



Setae are dusky when viewed in mass but pale when seen individual- 

 ly. They occur in full, flowing fascicles ; the preacicular barred setae are 

 shorter and fewer than postacicular setae (except in the first segment). 

 The barred setae are distally pointed, proximally transversely marked 

 with light and dark areas (figs. 3, 4). Postacicular setae are of 2 kinds; 

 the uppermost and lowermost in each branch are largely smooth, slender, 

 lanceolate; about 10 to 12 in the median part of fascicles differ in that 

 they have a large spur near the base of the extended part (figs. 5, 6) ; the 

 distal part is delicately spinous along the cutting edge. The specific name 

 refers to the spurred postacicular setae. 



Acicula are yellow, thick, single in rami; they taper distally to a 

 blunt tip. They may be completely embedded or project slightly from 

 the acutely conical acicular lobes. 



N. acrochaeta approaches N. incisa Malmgren in having acicular 

 lobes; it differs clearly from all known species of the genus in the 

 characteristic spurred postacicular seta. 



Holotype. — In the Swedish State Museum, Stockholm, Sweden. 



