264 DR. F. E. BEDDARD ON 
Oochoristica, and which are represented in the same figure for 
the purpose of a readier comparison. In Linstowia ameive the 
bundles contain a varying number of fibres—from as few as two 
or even one up to nine or ten. Midway between this inner 
longitudinal layer and the subcuticula is an outer layer of longi- 
tudinal fibres, which are largely implanted singly or in twos, and 
everywhere form a much thinner layer than the inner row. 
The water-vascular system is like that of other species of Lin- 
stowia; but it is not always quite easy to interpret the facts. 
In transverse sections I have seen the smaller dorsal vessel lying 
above the ventral either directly or more obliquely ; and this in 
quite neighbouring sections, in others of which the two vessels 
lay side by side, the dorsal outermost, 7.e. nearer to the nerve- 
cord. This is evidently due to the varying degree of contraction 
of the proglottids, a fact also emphasized by the zigzag course of 
the vessels when viewed in horizontal sections. I believe that 
the normal position of these vessels is side by side. The inner 
and larger of the two tubes, which I regard as the ventral vessel, 
gives off several branches in each segment, which are themselves 
branched. There also appear to be connections between the 
ventral and dorsal vessels. I cannot, however, give a map of this 
network. 
The testes lie posteriorly to the vitelline gland, and reach 
forward on either side of it; they do not, however, extend 
laterally of the ovary. In a given segment the testes were visible 
in 18 consecutive sections. The largest number counted in the 
middle of the series was 43. I therefore calculate the total 
number to be about 200. The testes do not extend laterally 
beyond the lateral water-vascular vessels. 
The genital ducts of this tapeworm open on to the exterior, as 
already mentioned, alternately, with, however, no absolute regu- 
larity in the alternation. They both open—the cirrus-sac in 
front of the vagina—into a genital cloaca, whose external pore is 
close to the anterior margin of the proglottid. This genital cloaca 
is separated into two regions, which are obviously of difierent 
morphological value. Outside is a funnel-shaped chamber, the 
apex of the funnel lying to the inside. In longitudinal sections 
through the cirrus-sac it was occasionally noted that the bottom 
of the funnel was almost completely closed, leaving but a narrow 
slit of communication with the inner chamber of the genital 
cloaca. The latter is roughly spherical in form, and receives the 
openings of the cirrus-sac and the vagina. Its depth is not very 
different from that of the outer funnel-shaped region. In longi- 
tudinal sections, it is seen to be marked off from the outer chamber 
by a projection on either side which is the expression in such a 
section of a circular fold. This fold is muscular and a thick 
layer of muscles, of which it is a part, encircles the whole of the 
spherical chamber of the genital cloaca. The cirrus-sae lies in 
the same straight line with the genital cloaca, and is thus at right 
angles with the long axis of the body of the worm. The cirrus- 
