380 ALFRED GIBBS BOURNE. 
vessels, V.T.’, of Segments VI, vit, and vir1, which arise not from the ventral 
vessel, but from the hearts of those segments; the ventro-tegumentary 
vessel, V. T.”, which arises from the heart of Segment vit and supplies 
Segments, Ix, x, part of x1, the nephridia of those segments, the sperm-sacs 
(Sem.), the prostate (pr.), and the ovaries (ov.); the ventro-tegumentary 
vessel of Segment x (V. T.’”) supplying only the ovary, which thus receives a 
double supply ; the ventro-tegumentary of Segment x11, the arrangement of 
which may serve as a type for those vessels in the rest of the body. Note 
also the hearts (H. vi1.—H. 1x.), shown cut short with some of the vasa- 
vasorum upon their walls. Note also the latero-longitudinal and subneural 
system, coloured blue. The three big trunks are seen to join together just 
behind septum 9/10 where the main trunk (shown cut short) passes upwards 
to open into the hearts of Segment rx (ep. fig. 33). The anterior and outer 
posterior trunks are seen to collect blood carried outwards by all the branches 
of the ventral vessel and hearts (except the hearts themselves) of Segments 
1 to rx; the inner posterior trunk is connected with the subneural vessel 
(not shown) by vessels marked a and 4; with it is also connected the “ veins ” 
of Segments x1 and xu. Except for the connection just mentioned, the 
“vein” of Segment x1, really a branch of the subneural, serves as a type of 
the arrangement of these vessels in the rest of the body; it is joined at z by 
the dorso-tegumentary vessel of the segment (D. T.), and passes on from e¢ to 
the subneural. 
All the vessels are drawn in as accurately as possible as far as they go. 
I have been unable to make quite sure about the ventro-intestinal of Seg- 
ments x, x1, and xu. I think there are no such vessels in Segments x and 
XI and a pair as usual in Segment xu, but these are not drawn. ‘The 
nephridiopores of Segments Ix—xIII are specially inserted on the left-hand 
side to show the relation of the blood-vessels to them. 
Generative Organs.—These are only indicated to show their relation 
to the various segments and septa. 4 and 9. Male and female pores. 
Sp. sac. Sperm-sac. pr. Prostate. Ov. Ovary. ovd. Oviduct. ovs. Ovisac. 
Sp. Spermatheca. cop. Copulatory pouch dissected out. 
Fic. 28.—M. ophidioides. Plan of the blood-vessels in a segment in 
the region of the gizzard, giz. D. v. Dorsal vessel. D. Zeg. Dorso-tegu- 
mentary vessel; this joins the branch of the subneural at z. D. Jn¢. Dorso- 
intestinal vessel ; its branches are seen to emerge from the gizzard wall and 
then join together. V. Zeg. Ventro-tegumentary vessel; this passes round 
towards the dorsal region, giving off branches to the nephridium, Nep/., and 
body-wall; all the blood distributed by it is carried back to the subneural by 
a branch of that vessel, Br. S. NV. 
Fie. 29.—M. ophidioides. View of a portion of the latero-longitudinal 
and subneural system. S. V. Subneural vessel; the most anterior branches 
of this to receive dorso-tegumentary vessels are those of Segment xv; the 
