;86 



Memoirs of the Indian Museum. 



[Voi.. V, 



o 



a 



The ist foot (fig. 8k, and text-fig. 4a) contains only the ventral setigerous divi- 

 sion. The dorsal and ventral cirri are long and slender. The median (?) and ven- 

 tral ligules are stout and conical. The ventral setigerous region consists of a fillet 

 forming a dome over the setae. The fillet is produced outwards into two conical 

 lobes, one in front of, and one behind the setae, and its lower edges are attached to 

 the ventral ligule. The spine pierces the anterior lobe of the fillet. In some speci- 

 mens there are two ventral spines. The setae are in three groups, a dorsal group 

 consisting of a single row with falcate heterogomphs in front, long-tipped (spinose) 



homogomphs behind, and two ventral 

 groups, an anterior group of falcate 

 heterogomphs, and a posterior group 

 of spinose heterogomphs. The 2nd 

 foot is similar. The dorsal division 



O^T^>. />• appears in the 3rd foot. 



(i i) &w^ The I0th foot ( fig ' 8f ' and text " 



V: ~~7 / \ fig. 46) exhibits the normal condi- 



tion. The dorsal cirrus is long, great- 

 ly surpassing the dorsal ligule, but 

 the ventral cirrus is small. The dor- 

 sal, median, and ventral ligules are 

 large, thick, and bluntly rounded, 

 the dorsal being the largest. In the 

 dorsal division the fillet has a pro- 

 minent pointed anterior lobe, and 

 a smaller rounded posterior one, and 

 its lower edges are attached to the 

 median lobe, before and behind the 

 spine. The setae are all homogomphs 

 (fig. 8n) with long slender terminal 

 pieces. The ventral division is as in 

 the first foot. 



In the succeeding feet the lobes 

 become gradually more elongate and 

 pointed. The dorsal setigerous lobe decreases in size, and fuses more or less com- 

 pletely with the median ligule. The dorsal part of the foot, including the median 

 ligule, increases in size relatively to the ventral part and projects beyond it. 



In the 50th foot (fig. 8g and text-fig. 4c) the dorsal cirrus is long and 

 slender, the ventral cirrus small and thin. The dorsal and median ligules are 

 large and pointed. The dorsal setigerous lobe is represented by a small swelling, 

 pierced by the spine, on the upper side of the median ligule, and by a small and 

 indistinct fillet guarding the dorsal setae. The ventral ligule is much smaller. 

 The ventral fillet, with its two lobes, is as before, and forms an arch above and 

 below the setae. 



Text-fig. 4. — Parapodial diagrams of Nereis chilkaèn* 



szSjSp. nov. 



a. ist foot. b. 10th foot. c. 50th foot. 



• = Homogoinph setae with long spinous tips ; o = Hetero- 

 gomph setae with long spinous tips ; x = Heterogomph setae 

 with long falcate tips ; • = Heterogomph setae with thick shafts 

 and tips. 



