6oo Memoirs of the Indian Museum. [Vol. V, 



completely occupied by the two blood-vessels. There are 13 pairs of branches, each 

 bearing a double row of slender filaments which are nearly as long as the branches. 

 The slender dorsal cirrus is carried at the tip of the stem. The 5th, 6th and 7th 

 pairs are similar, with 14 pairs of branches. The 8th and last pair, on the 22nd feet, 

 are much smaller, with 9 or 10 pairs of branches. The base of the dorsal cirrus of 

 the 23rd foot is short, simple, and slender. 



In the anterior region of the body the feet differ so much that it is necessary to 

 examine them all carefully. The first foot (fig. 4D, and text-fig. ga) consists only of 

 the dorsal cirrus with a lobe beneath it, which is either the dorsal or the median 

 ligule, and the ventral setigerous division. The dorsal cirrus, seated on a jointed 

 base, is long and tapering. The ventral division is composed of 6 or 8 lobes and the 

 ventral cirrus. The setae are in two groups, each guarded by a fillet, the single 

 spine lying between the groups. They are all homogomph setae (fig. 41,), with long 

 minutely serrate or smooth terminal pieces. A single seta in the posterior row of the 

 upper group differs from the rest in having a shorter terminal piece with long stout 

 teeth (fig. 4M). The arrangement of the lobes and setae is shown in text-fig. ga. 

 Sometimes the lobe b is absent, sometimes a and b. The foot is very vascular, 

 blood-vessels passing into each lobe. The 2nd foot (text-fig. gb) resembles the ist, 

 but it has 11 lobes in addition to the ventral cirrus in the ventral division, and two 

 setae with coarsely serrate terminal pieces. The lowest ventral setae, as in all other 

 segments, have shorter terminal pieces than those in the upper part of the foot. 



In the 3rd foot (text-fig. 9c) the dorsal setigerous division appears. It consists 

 in addition to the dorsal cirrus and dorsal ligule, of two other lobes, the posterior one 

 being the median ligule, between which lies the spine. Above and behind the anterior 

 lobe is a group of a few slender homogomphs like those in the ventral division, 

 guarded externally by a fillet. The ventral division consists of 15 lobes, in addition 

 -to the ventral cirrus. 



The 4th foot is very similar (text-fig. gd), especially the dorsal division. In the 

 ventral division the setae now form a continuous series, guarded externally by a 

 fillet. There are 16 lobes in the ventral division, of which 9 are behind, and 7 in 

 front of the setae. The coarsely serrate setae are more numerous. The base of the 

 dorsal cirrus shows signs of flattening. 



The 5th foot is similar to the 4th, with more numerous setae. The 10th foot 

 (fig. 4E, and text-fig. ge) shows still greater complexity. The base of the dorsal 

 cirrus is large and flattened. In the dorsal division the setae are more numerous, 

 and an additional small lobe lies in front of the spine. The ventral division has 18 

 or 19 lobes, of which 12 form a fringe behind the setae, whilst the anterior 6 or 7 

 lobes are almost surrounded by the setigerous fillet. The upper posterior lobe of the 

 ventral division is flattened at the base and pointed distally. The nth-i4th feet 

 are similar. 



At the 15th foot (fig. 4F, and text-fig.. 9/), which carries the first branchia, there 

 is a marked change. The dorsal division is reduced to the two posterior lobes, 

 the upper one corresponding to the dorsal ligule of the anterior feet, the lower one to 



