592 Memoirs of the Indian Museum. [Vol. V, 



tips have been replaced by falcate hemigomphs (fig. 91,) especially in the lowest group. 

 These setae have very elongate spinous tips, and the point is boldly curved. 



In the 50th foot (fig. 9G, and text-fig. $d) there is no marked change in the 

 dorsal division. In the ventral division the upper anterior group of setae are all 

 falcate hemigomphs. A few hemigomphs with short coarsely serrate pointed tips 

 appear in the posterior row behind the spine. 



In the 60th foot the two anterior lobes of the ventral division are smaller, and the 

 setae are fewer in number. The falcate hemigomphs have disappeared and are not 

 present in the succeeding feet. In the 80th foot the upper anterior lobe of the ventral 

 division is reduced to a small papilla, scarcely visible. In the 90th foot it has quite 

 disappeared. 



In the 1 ooth foot (fig. 9H, and text-fig. 50) all the foot lobes are slender and 

 sharply pointed. 



In the last few segments the dorsal cirrus increases in length till it surpasses the 

 dorsal lobe. The dorsal setigerous lobe becomes small and rudimentary. There 

 appear to be no true heterogomph setae in this species, their place being taken by setae 

 having the shafts ending in the intermediate condition which has been termed " hemi- 

 gomph." There is no sharp distinction to be drawn between these various types, 

 the falcate seta shown in fig. ojl, being nearer the true heterogomph condition than the 

 coarsely spinose seta shown in fig. 9K. 



The anal segment is conical, the anus forming a terminal slit. The anal cirri are 

 short and slender, a little shorter than the anterior ventral tentacular cirri. There is 

 a ring of reddish brown pigment (or glands) round the middle of the anal segment. 



In a number of the specimens, the body cavity was full of eggs, but no indica- 

 tion of change to the Heteronereis condition was observed. This species is charac- 

 terised by the armature of the proboscis, the structure of the feet, and the shape and 

 arrangement of the setae, especially by the absence of falcate setae from the anterior 

 and posterior segments. The girdle of glands on each segment is also very charac- 

 teristic. Nereis kerguelensis, Mcintosh, has some points of resemblance to this species 

 but is otherwise not closely related to it. Of greater interest is a comparison with Nereis 

 reducta (p. 593). In both species the paragnaths of the basal ring are greatly reduced 

 in size and number, so as to be almost rudimentary. The dorsal setigerous division 

 in N. glandicincta, though small, is much more developed than that of N. reducta. 

 In both species the dorsal and ventral cirri are short, but N. glandicincta has a 

 prominent dorsal ligule, whilst that of N. reducta is small in the anterior and poste- 

 rior segments. In N . reducta the spinous heterogomph setae are absent in the 

 anterior segments, and only in small numbers elsewhere, whilst in N. glandicincta it is 

 the falcate setae which are absent from the anterior and posterior segments. These 

 resemblances indicate no close affinity, but are probably due to convergence. They 

 are mostly of a negative character, and may be due to modification fitting for life in 

 brackish or freshwater. It is significant that Lycastis, the genus found most fre- 

 quently in fresh and brackish water, shows great simplicity in the structure of the foot, 

 little variety in the shape of the setae, and has no paragnaths on the proboscis. 



