30 
mon genital pore, lined with thick cuticle just 
before uniting with ejaculatory duct. 
discussion: This genus bears a certain re- 
semblance to Parabothriocephaloides Yamaguti, 
1934 in gross anatomy, but differs from it in 
that the scolex is provided on each flat surface 
with an oval bothrium, and in the distribution 
of testes, etc. From these differences it seems 
certain that the present genus, obviously para- 
bothriocephalid in structure, represents a distinct 
genus, for which the name Metabothriocephalus 
is proposed, with the following diagnosis: 
Metabothriocephalus n. g. 
generic diagnosis: Parabothriocephalidae. 
Scolex not marked off from neck, with an in- 
distinct apical disc followed on each flat surface 
by a small oval subapical bothrium surrounded 
by condensed tissue. Neck present. Strobila 
comparatively fleshy, with complete segmenta- 
tion; proglottides wider than long throughout 
strobila, with salient posterior border and nearly 
parallel lateral margins. Inner longitudinal 
muscle bundles strongly developed anteriorly, 
though individual bundles are rather wide 
apart one from another. Testes medullary, in 
small number medial to excretory stems. Cirrus 
pouch reduced. Ejaculatory duct opening with 
vagina by a small common pore dorsomarginally 
at a pre-equatorial level, alternating irregularly 
from side to side. Ovary transversely elongated, 
not two-winged, slightly submedian (on pore 
side) near posterior end of proglottis. Uterine 
duct winding in median and submedian fields; 
uterine sac practically median, opening mid- 
ventrally near anterior end of proglottis. Vagina 
straight, joining ejaculatory duct at genital pore. 
Vitellaria entirely cortical, diffuse, continuous 
from proglottis to proglottis. Eggs rather thick- 
shelled, operculate, with unsegmented ova. 
Parasitic in intestine of marine teleosts. 
type species: M. menpachi n. sp., in Myri- 
pristis spp.; Hawaii. 
PACIFIC SCIENCE, Vol. XXII, January 1968 
PTYCHOBOTHRIIDAE Liihe, 1902 
6. Alio ptycho bothrium spilonotopteri n. g., 
n. sp. 
Fig. 6A-D 
habitat: Small intestine of Cypselurus sp Ho- 
rn 0 top ter us; Hawaii. 
holotype : U. S. Nat. Mus. Helm. Coll, 
S. Y. No. 376. 
description (based on four immature and 
three gravid specimens; unless otherwise indi- 
cated the following description is based on 
whole gravid mounts and serial sections of 
gravid proglottides) : Strobilas over 30 mm 
long are all gravid. Scolex arrowhead-shaped 
in lateral view, with edges markedly crenulated 
and enclosing deep longitudinal groove, 2.8 mm 
long, 1.7 mm wide dorsoventrally in the type; 
its apex blunt-pointed, two posterior ends 
widely divergent or hanging down, one on 
each side of strobila. Neck absent. Proglottides 
transversely elongated, 0.1 X °-5 Dim at an- 
terior end directly following scolex, with pos- 
terior border somewhat craspedote or not; 
gravid proglottides very variable in length and 
width, ranging from 0.18 to 0.9 mm in length 
and from 0.9 to 2.2 mm in width, depending 
on the degree of pressure applied on cover 
glass. Transverse sections of unflattened gravid 
specimens fusiform, 0.4-1. 7 mm wide, 0. 1-0.5 
mm thick, showing notches in dorsal and ven- 
tral midlines, corresponding to genital atrium 
and uterine pore, respectively. Cuticle thick, 
with striations at right angles to the surface. 
Inner longitudinal muscle bundles isolated in 
lateral fields, but forming a conspicuous layer 
outside as well as inside of layer of vitellaria 
in median and submedian fields, with distinct 
median break corresponding to genital and 
uterine pores. Dorsal longitudinal excretory 
stem with thicker walls than ventral stem, lying 
lateral to ventral stem, latter stems separated 
one from the other by uterine coils; two or 
more, narrower, ventral vessels are seen forming 
anastomoses. 
Testes confined to submedian medulla im- 
Figs. 5 A—E. Metabothriocephalus menpachi n. g., n. sp. A, scolex of holotype from Myripristis argyromus, 
ventral view; B, immature proglottis of holotype, ventral view; C, mature proglottis of paratype from Myri- 
pristis argyromus, dorsal view; D, fully gravid proglottis of holotype, ventral view; E, transverse section of 
gravid proglottis of paratype from Myripristis argyromus. 
