MONILIGASTER GRANDIS, A. G. B. 381 
dorso-tegumentary vessel joins the subneural branch at z. The latero-longi- 
tudinals a. 4., a. 6. have come down at a.a. from the head region; all the 
blood brought forward by the subneural passes into them; more blood always 
passes on the right side than on the left ; all this blood is carried by c.,c., ¢., ¢. 
into the hearts of Segments viir and 1x. The subneural itself is seen to 
come to an end shortly after giving branches to the latero-longitudinal 
vessels. What little blood gets into this anterior prolongation must be 
carried backwards to pass into the latero-longitudinal. 
Fic. 30.—M. pellucida. View of the supra-intestinal vessel, S. I., and 
its branches. The dorsal vessel is not drawn; it has no connection in this 
species with the hearts of Segment 1x (H. 1x). The supra-intestinal arises 
on the gizzard at 7, and receives vessels from the walls of that organ and 
from those of the cesophagus in front, d., d. It also receives all the blood 
from the latero-longitudinal and subneural vessels by e.,e. It then bifurcates 
and empties its blood into the hearts of Segment 1x. a. Latero-longitudinal 
vessel from the head region. 4. Portion of the latero-longitudinal which is 
connected with the subneural. c. Vessels from the sperm-sacs. sp. Pros- 
tates, &. 
PLATE 26. 
Fic. 31.—M. grandis. Diagram of the vessels in any Segment from x11 
onwards. B.w. Body-wall. Inv. Intestine. On the right hand is shown 
the nephridium. 2. The nephridiopore. The sets are shown in their right 
position with regard to the gaps. The dorsal blood-vessel, D. V., is shown 
with its dorso-tegumentary branch D. T., and its dorso-intestinal branch, D. I. 
The former joins the branch of S. N., the subneural, at z. The ventral 
vessel, V. V., is shown with its ventro-tegumentary branch, V. T., and its 
ventro-intestinal branch, V. I. n., n., n. Nephridial arteries and veins. 
Fic. 32.—M. grandis. Diagram of the vessels in Segment vi. The 
heart is shown on the left side with the muscular bulb interposed between it 
and the ventral vessel, V. V. The ventro-intestinal branch is shown going 
to the cesophageal wall. The ventro-tegumentary vessel is shown arising 
from the heart just beyond the muscular bulb, giving off a branch to the 
heart-wall (this passes on to the wall of the dorsal vessel also) and branches 
to the body-wall. The main trunk of the latero-longitudinal and subneural 
system, viz. the anterior latero-longitudinal vessel, L. L., is shown in its 
proper position, and is seen to receive veins from the cesophageal wall and 
the wall of the heart and the body-wall. 
Fic. 33.—M., grandis. Diagram of some of the vessels of Segment 1x 
to show the latero-longitudinal vessels (each now composed of its three ~ 
branches, anterior and two posterior, cp. fig. 27) passing downwards and 
