76 Giri/nnefJi BacJia/nan : 



the nlimeiitarv canal, and from this the supra-intestinal arises, 

 which runs backwards to the posterior mesentery of 15, and 

 forwards to the front of 8. In 13 and 14 it gives off a vessel 

 on each side to the alimentary canal, which opens into the 

 sub-intestinal, there being- no branch from the dorsal in these 

 segments. In segments 10, 11 and 12 a pair of hearts arise 

 from the dorsal and supra-intestinal in the posterior part of 

 the segment, opening into the ventral, markedly on its under 

 side. In segments 9-5 the dorsal gives off posteriorly in each 

 segment a commissura] vessel on each side, having a small 

 connection with the ventral, and ending clearly on the septum. 

 From segment 9 forwards the ventral is very small indeed, and 

 its connection with these vessels becomes more and more in- 

 distinct. It seems to break up soon after its junction with 

 that in segment 5, but may continue to the most anterior end. 

 In segments 4, 3 and 2 the branches from the dorsal break up 

 on' the wall of the alimentary canal, while that in 5 gives off a 

 lateral, running forward and downward for a short distance, 

 and backwards and upwards at first, then dipping down as the 

 sub-intestinal on each side, ending at the back of 16 as de- 

 scribed. From 8-14 this vessel receives branches from the 

 alimentary canal, derived from the supra-intestinal which ends 

 blindlv in front of segment 8. 



16. — Dipopochaeta yarpaensis, Spencer. 



Pepichaeta yappaensis, Spencer. P.R.S. Vict., 1892. 



Plate XYI., Fig. 10. 



Dissection. — Dorsal vessel single, swollen in segments 13-18, 

 less so in 10-12. At the front end it divides and runs round, 

 apparently joining with the ventral, but both vessels are here 

 small. At the hinder end the dorsal and ventral are joined by 

 a single pair of commissural vessels, one on each side. Ten 

 segments from the last, these, in one specimen, appeared to 

 come off, not in the middle of the segment as is the case 

 further forward, but down the mesentery. As, however, this 

 arrangement was less marked in the next examination, and as 

 the muscles in the mesentery are here very thick, this ap}>ear- 



