362 Records of the Indian Museum. [Vol. X, 



Of the septa, the first, *, is thm ; ^-\\ are thickened, —l 

 slightly, f more so, h-t? markedly, \l slightly. The septal gland of 

 segment viii is somewhat smaller than those of the foregoing 

 segments, but not very markedly so. A large amount of glan- 

 dular tissue similar to that of the septal glands exists in front of 

 septum I, lying on the pharynx and mingling with the muscular 

 strands of this region ; the whole forms a considerable mass in 

 front of the first septum, and it therefore seems hardly correct, in 

 the specific definition, to limit the septal glands to segments v-viii. 

 The clitellum extends from ^xiii to xix or |xx (= 6^ or 7). The 

 prostates extend backwards only a short distance behind the male 

 pore, and do not reach the posterior limit of the clitellum. 



The circulatory system was examined in the living worm by 

 the microscope ; and many of the results were checked by serial 

 sections. 



The dorsal vessel lies above and separate from the gut-wall ; 

 it is however invested by chloragogen cells above the intestine. 

 It is contractile ; the contractions in its anterior part (segments 

 ii-vii) are often antero-posterior in direction. 



There is a very short supra-intestinal vessel, connected with 

 the upper ends of the hearts. It extends only over two segments 

 or a little more, appearing posteriorly just behind the second 

 heart, and becoming lost on the oesophagus anteriorly about the 

 place where the oesophageal diverticula are connected with the 

 ahmentary tube (segment ix). 



Lateral oesophageal vessels are present ; they appear, in an 

 examination of the living animal, to be continued back as lateral 

 channels in the intestinal wall, but these are not discoverable in sec- 

 tions. They are connected with the copious plexus on the oesopha- 

 o-eal diverticula; they are continued forwards, with a sinuous 

 course, as far as segment ii ; they give numerous branches, and in 

 the region of the septal glands run on the inner face of the glands, 

 in the gland capsule, and unconnected with the oesophageal wall. 



The ventral vessel is very small in the anterior part of 

 the body, as far back as the hearts ; and its connection with the 

 point of junction of the anterior hearts is very narrow. Poste- 

 riorly it has the usual relations. 



The hearts are in segments x and xi, on the posterior septa 

 of these segments (septa if and \\). The hearts of the same side 

 contract as a rule alternately, but irregularly (under chloretone), 

 —seldom simultaneously. Those of opposite sides but of the 

 same pair also seldom contract simultaneously, but here again 

 there is no rule. The contraction of the hearts is independent of 

 that of the dorsal vessel. The hearts are connected below with the 

 ventral, above with both dorsal and supra-intestinal vessels. 



There are six loops on each side in front of the hearts, in 

 segments iv-ix ; they run in the substance of the septal glands, or 

 on their outer surface. It is possible however that the number is 

 not constant ; in one specimen there were five obvious loops on 

 one side, in segments ix to v, of which that in v was the largest ; 



