22 
PACIFIC SCIENCE, Vol. XXII, January 1968 
ABBREVIATIONS USED IN FIGURES 
b 
bothrium 
ex 
excretory 
s 
sucker 
c 
cirrus 
stem 
sph 
sphincter 
cf 
collarlike 
ga 
genital 
of 
fold 
atrium 
vagina 
Cp 
cirrus 
gp 
genital 
t 
testis 
pouch 
pore 
u 
uterus 
ds 
ductus 
il 
inner lon- 
ud 
uterine 
seminalis 
gitudinal 
duct 
muscle 
cvp 
cirrovaginal 
up 
uterine 
pore 
rap 
muscular 
pore 
ds 
dorsal 
pad 
vd 
vas 
vessel 
n 
nerve 
deferens 
trunk 
ej 
ejaculatory 
vg 
vagina 
duct 
0 
ovary 
vt 
vitel- 
ev 
excretory 
oc 
oocapt 
larium 
vesicle 
rs 
receptac- 
vv 
ventral 
ulum 
vessel 
seminis 
cupied by wide, paired, sigmoid, excretory 
vesicles up to 0.2 mm wide; the latter vesicles 
unite in the median line and open outside 0.1 
mm from the posteriormost margin. Dorsal and 
ventral longitudinal excretory vessels running 
at junction of lateral with middle third of 
proglottis or just medial to it near lateral end 
of medulla, ventral to genital ducts and lateral 
to nerve trunk in gravid proglottides. Nerve 
trunk dorsal to vas deferens and vagina. Inner 
longitudinal muscle bundles strongly developed 
throughout strobila, forming a distinct boundary 
between medulla and cortex. 
Testes rounded or elongate, numerous, 
rather small, arranged in one layer or two in 
dorsal medulla, continuously from end to end, 
leaving part of medulla free where the ovary 
and uterus are situated. In the gravid proglot- 
tides the testes are atrophied as they approach 
the senile segments. In some sections one testis 
or two may lie exceptionally in the dorsal cortex 
immediately outside the inner longitudinal 
muscle bundles or among these bundles. Cirrus 
pouch pyriform, with thick muscular wall, 
0.15-0.2 mm wide in the type, situated oblique- 
transversely, mostly in lateral marginal cortex, 
with its base extending into outer end of me- 
dulla or not, containing narrow convoluted 
ejaculatory duct and a bulbous cirrus, which 
opens at the tip of the pouch into the genital 
atrium. The cuticular lining of the bulbous 
cirrus forms a reticular basket-like structure 
(Fig. 1H), which is continued onto the ejacula- 
tory duct, where the network is reduced and 
becomes so fine that it appears like cilia in cross 
section. Genital pore lateral, irregularly alter- 
nating. 
Ovary transversely elongated along anterior 
median ventral margin of medulla, just inside 
inner longitudinal muscle bundles, up to 0.45 
mm transversely in the type. Shell gland com- 
plex posterodorsolateral to oocapt, at median 
dorsal prominence of ovary. Uterus winding 
transversely dorsal to ovary, extending laterad 
into space between lateral ends of ovary and 
lateral testes; it may reach to the nerve trunk 
passing ventral to the outermost testes. Finally 
the uterus empties into the uterine sac, which 
lies in the ventral cortex in about the same 
sagittal plane as the dorsal collecting excretory 
vessel. Uterine pore wide, about one-third of 
proglottis width from lateral margin or a little 
more laterally. Eggs elliptical, comparatively 
thick-shelled, embryonated, 76-1 OOp X 46-54p 
in sections. Vitelline follicles small, round, ex- 
tending profusely in almost entire cortical 
parenchyma of marginal laminae. Vitelline reser- 
voir inconspicuous, just ventral to shell gland 
complex. Vagina opening into genital atrium 
ventral to cirrus pouch; it is enlarged at its 
terminal portion, lined with smooth cuticle, the 
remaining portion is narrow, tubular, and lined 
with cilia. 
discussion : This genus differs from the most 
closely related Eubothrium Nybelin, 1922, as 
shown in Table 1. 
These morphological differences, combined 
with difference in host, are sufficient to justify 
Figs. 1 A-H. Pseudeubothrium xiphiados n. g., n. sp. A, scolex of paratype, dorsoventral view; B, posterior 
extremity of holotype, ventral view; C, transverse section of anterior part of paratype; D, transverse section of 
immature proglottis of paratype; E, transverse section of mature proglottis of paratype; F, transverse section of 
gravid proglottis through ovary; G, transverse section of lateral portion of gravid proglottis through genital and 
uterine pores; H, same showing basketlike structure of lining of cirrus. 
