I9I4'] J- Stephenson : Oligochaeta from Northern India. 331 



but are sometimes present in the posterior portion of the body 

 also. 



Two pairs of gills (text-fig. 6) stumpy and cylindrical, arise 

 within the margin of the anal funnel ; a third pair is formed ante- 

 riorly to these by a projection of the funnel margin; and there is a 

 similar small fourth, most anterior or dorsal pair, which might be 

 considered as a portion of the third pair separated off by a cleft 

 in the margin of the funnel. The appearance is sketched in text- 

 fig. 6, and resembles that figured by Bousfield (2), except that the 

 interval in the middle line between the fourth gills of each side is 

 much less in my specimens. It is usual (iVLichaelsen, 3 ; Bousfield, 

 2) to describe only one pair of secondary branchiae, or projection.s 

 of the funnel margin, in D. limosa; but, as Bousfield's figures 

 (drawn probably in a more completely expanded condition of the 

 funnel than mine) very plainly show, there are really two such 

 pairs. All four pairs of gills are vascular and all four show in 

 their interior a regular series of star-shaped or spindle-shaped 

 cells, stretching by means of their processes across the cavit}' of 

 the gill-process. 



The dorsal setae begin in the sixth segment, and each bundle 

 consists as a rule of one capillary and one needle seta. The capil- 

 lary setae are on an average 190,' long. The needles are 66/' 

 long, are bifid at the end, with the prongs small, equal or sub- 

 equal; the nodulus is about 19/^ from the distal end, and the 

 shaft has a slight sickle-shaped curve between the nodulus and the 

 free extremity. 



The ventral setae, beginning in segment ii, are either three or 

 four per bundle. There is a marked difference between those of 

 segments ii — v and of the rest of the body. 



In the anterior segments (ii — v) the curves of the shaft are 

 slight; the total length is about 127/u, and the breadth 2"5,u. The 

 prongs of the fork are separated by a very narrow angle, and both 

 prongs are comparatively long; the distal is the longer, — one and 

 a half times as long as the proximal, and equal to it in thickness. 

 The nodulus is proximal to the middle of the shaft, thus: — 



proximal to nodulus : distal to nodulus ;; 50^1 : yS/i. 

 or again ,, ,, ,, : ,, ,, :: 5i,« : 75m- 



In the remaining segments (vi to posterior end) the setae are 

 much shorter, and the curves of the shaft more pronounced. 

 The prongs are comparatively short, and the angle between them 

 is moderately wide. The distal prong of the fork is very slightly 

 longer than, and is only half as thick at the base as, the proximal 

 prong. The average length is 70/u,, and thickness 3/^. The nodulus 

 is distal to the middle of the shaft ; but its position varies, as 

 will be explained immediately. 



Where these setae are four per bundle, they can be distin- 

 guished as two couples, an inner and an outer (or a more ventrally 

 and a more laterally situated); the outer couple is the shorter, 

 and is especially short from nodulus to tip; thus, — outer couple 



