Pacific Thaliacea — Tokioka and Berner 
323 
Fig. 5. A, Doliopsoides horizoni Tokioka and Berner 1958, stomach showing protuberances. B, Doliopsoides hori- 
zon i, ventral protuberance of phorozooid. 
One individual of the phorozooid genera- 
tion was found among the specimens. It has 
a short ventral protuberance into which both 
ends of muscle VII project. 
COMPARISON OF ALIMENTARY REGION OF 
Cyclosalpa strongylenteron and C. bakeri 
In the examination of aggregate individuals 
of Cyclosalpa strongylenteron Berner 1955, some 
distinct asymmetries were found in the ar- 
rangement of the alimentary organs and 
gonads. These features differed somewhat 
between the dextral and sinistral individuals, 
although the musculature showed almost 
complete symmetry. The features of the ali- 
mentary organs and the gonads are compared 
with those of the aggregate form of C. bakeri 
Ritter 1905, whose visceral portion closely 
resembles that of C. strongylenteron . 
In Cyclosalpa strongylenteron Berner 1955 
(Figs. 6A, B, 7) the dextral individuals are 
those derived from the right side of the stolon 
when it is placed so that the stolo-individuals 
are situated dorsal side up, with the posterior 
end toward the right and with the proximal 
end of the stolon pointing away from the 
observer. The sinistral individuals are those 
derived from the left side of the stolon. 
In the dextral individuals the intestinal loop 
is U-shaped. The anus {an.) opens on the left 
side at a level slightly anterior to the oesopha- 
geal opening ( oe . op.). There is a large elon- 
gate blind sac or caecum (l.c.) attached to the 
ventral side of the lower branch of the loop, 
about one third of the way between the 
oesophageal opening and the posterior mar- 
gin of the loop. The tip of the caecum reaches 
posteriorly nearly to the posterior margin of 
the gut loop but seldom beyond it. A small 
sac or protuberance (r.c.) is found on the left 
wall of the alimentary tract just dorsal to the 
base of the large caecum (Fig. 7). The duct of 
the circum-intestinal gland ( d.c.g .) opens into 
the tip of this small sac, which could be con- 
sidered merely a swelling of the proximal end 
of the duct. It is clear, however, that it is 
actually a projection of the alimentary tract. 
The swollen portion is stained reddish orange 
by Rose Bengal, like the alimentary tract, 
rather than purplish red like the duct. The 
relative positions of the small and large sacs 
indicate that they are the right and left 
caeca respectively. 
The testis (t.) is about half the length of the 
left caecum and is situated on the right side 
of the ventral branch of the intestinal loop 
near its posterior margin. The vas deferens 
{v.d.) crosses the duct of the circum-intestinal 
gland on the left side and opens into the 
atrial cavity just in front of the point where 
the dorsal visceral muscles (l.x. and r.x.) from 
each side unite. These joined muscles project 
posteriorly into the center of the intestinal 
loop passing to the right of both the vas 
deferens and the duct of the circum-intestinal 
gland. The left visceral muscle {l.x.') runs 
along the ventral side of the intestinal loop, 
