136 
PACIFIC SCIENCE, Vol XII, April, 1958 
Fig. 1. Doliopsoides horizoni n. sp., gonozooid from 
left side. I— VIII, circular body muscles; an ., anus; c.g., 
ciliated groove; d.g., dorsal ganglion; d.gl., dorsal gill; 
ed., endostyle; ht., heart; int., intestine; l.l.m., lateral 
longitudinal muscle; o., mature ovum; oe., oesophagus; 
oe.op., oesophageal opening; ov., ovary; p.b., peripharyn- 
geal band; st., stomach; tes., testis; v.d., vas deferens; 
v.gl., ventral gill; v.l.m., ventral longitudinal muscle. 
and V, one on each side of the body. These 
muscles extend from just below the mid- 
lateral portion of muscle IV obliquely up- 
ward, joining muscle V just above the mid- 
lateral line. Another narrow longitudinal 
muscle (ventral longitudinal muscle, v.l.m.) 
connects muscles III and IV along the mid- 
ventral line. 
The endostyle (ed.) is long and rather thick 
although its consistency does not seem to be 
compact. Anteriorly it begins just behind 
muscle II and extends posteriorly to slightly 
beyond the middle of the fourth intermuscular 
zone. The anterior margins of the peripharyn- 
geal bands (p.b.) project slightly in front of 
muscle II. The ciliated groove (c.g.) is lo- 
cated near the middle of the second inter- 
muscular zone, the dorsal ganglion (d.g.) is 
in the same zone near muscle III. The gill 
consists of a dorsal (d.gl.) and a ventral pair 
(v.gl.) of lamellae. It extends dorsally to the 
level of the ends of muscle V and ventrally 
to the middle of the fourth intermuscular 
zone or slightly anterior to it. The dorsal and 
ventral lamellae approach just above the junc- 
ture of muscle VI and VII. The gill bears in 
all 30 to 40 elongate stigmata. 
The oesophageal opening (oe.op.) is lo- 
cated on the dorsomedian line near muscle 
VII, the oesophagus (oe.) itself is strongly 
curved. The stomach (st.) is situated vertically 
and in outline roughly forms an elongate 
triangle with the pyloric portion the narrow- 
est. The intestine (int.) forms a U-shaped loop 
in the saggital plane of the body which ends 
with the anus (an.) near the pyloric end of the 
stomach. The proximal portion of the loop 
is somewhat thinner than the other portions 
and it is not certain whether this represents a 
hind stomach. The formation of fecal pellets 
was observed in all three specimens. Kruger 
in his description of D. meteori mentioned the 
formation of "Kotballen” in the intestine. 
There is a thin but distinct vessel connecting 
the pyloric portion of the stomach with the 
middle of the ventral branch of the intestinal 
loop. The ovary (ov.) is situated just dorsal 
to the posterior end of the endostyle and 
slightly to the right of the median line. In one 
specimen the ovary contains a large mature 
ovum (o.). The oviduct is so short as to be 
practically absent. The testis (tes.) is located 
between the ovary and the intestinal loop. It 
consists of two spherical lobes. The vas 
deferens (v.d.) is short but distinct, and ex- 
tends from the testicular lobes to near the 
ovary, probably in the region of the female 
genital pore. The heart (ht.) lies between the 
posterior end of the endostyle and muscle V. 
REMARKS 
This form is evidentally very closely related 
to Doliopsoides meteori (Kruger, 1939)* Kruger’s 
genus and species were described from a 
