Digenetic Trematodes, I — Yamaguti 
465 
pact, overlapping posterior end of ovary. Ex- 
cretory vesicle tubular, long, reaching to ovary, 
with terminal pore between two ani. 
DISCUSSION : This genus is undoubtedly closely 
related to Acaenodera Manter and Pritchard, 
I960, but differs from it distinctly in possess- 
ing discoid, cuticular, cervical projections in- 
stead of spines. I prefer to regard this differ- 
ence as of generic importance. It is defined as 
follows : 
Pseudacaenodera n. gen. 
GENERIC DIAGNOSIS: Acanthocolpidae, Acan- 
thocolpinae. Body slender, armed in cervical 
region with longitudinal rows of flattened 
conical or discoid cuticular projections both 
ventrally and laterally. Oral sucker terminal, 
bowl-shaped, prepharynx very long, widened 
posteriorly; pharynx barrel-shaped, esophagus 
very short, ceca opening outside by separate ani 
at posterior extremity. Acetabulum larger than 
oral sucker, less than one-third of body length 
from anterior extremity. Testes tandem, in pos- 
terior third of body. Cirrus pouch claviform, 
almost completely occupied by seminal vesicle, 
containing neither cirrus nor prostatic complex. 
Genital sinus tubular, opening medianly on an- 
terior border of acetabulum. Ovary median, pre- 
testicular. No seminal receptacle. Laurer’s canal 
present. Vitellaria extending along ceca from 
level of seminal vesicle to posterior extremity; 
vitelline reservoir overlapping ovary. Uterus 
winding in intercecal field between ovary and 
acetabulum; eggs oval, medium-sized. Excretory 
vesicle long, tubular, with terminal pore. Para- 
sitic in intestine of marine teleosts. 
TYPE SPECIES: P. cristata n. sp., in Conger 
marginatus; Maui island, Hawaii. 
4. Albulatrema ovale n. gen., n. sp. 
Fig. 4 
HABITAT: Swimbladder of Alhula vulpes 
(local name "oio”); Hawaii. 
HOLOTYPE: U. S. Nat. Mus. Helm. Coll., S.Y. 
No. 22. 
DESCRIPTION (based on 20 strongly flattened, 
whole mounts ) : Body subglobular to oval or 
pyriform, 3.4-6.2 mm long, 2. 5-4.5 mm wide 
in midregion. Cuticle smooth; outer circular 
and inner longitudinal subcuticular muscles well 
developed; parenchyma loose-meshed, traversed 
by strong muscle bundles running in different 
directions. Oral sucker terminal, 0.3-0.4 X 0.5- 
0.7 mm, directly followed by muscular pharynx 
0.3-0.35 mm long by 0.15-0.45 mm wide. 
Esophagus very short; ceca wide, undulating, 
ventrolateral or ventral to testis, lateral or ven- 
tral to ovary and vitelline gland, and ventral to 
uterus, terminating at posterior extremity, one 
on each side of excretory vesicle. Acetabulum 
0.6-0.85 X 0.65-0.98 mm, situated at posterior 
half of anterior third of body. 
Testes oval, 1.0-1. 5 X 0.54-1.1 mm, placed 
almost symmetrically posterolateral to acetabu- 
lum; vas efferens arising from anterior end of 
each testis, joining together in median line dor- 
sal to anterior part of acetabulum; vas deferens 
narrow proximally, but becoming wider and 
strongly muscular, forming a conspicuously 
winding or convoluted mass which is sharply 
delimited from the surrounding parenchyma by 
a capsule of apparently muscular element an- 
terodorsal to acetabulum; seminal vesicle ab- 
sent; pars prostatica sigmoid, strongly muscular, 
surrounded by well-developed prostate cells 
which are sharply delimited from the surround- 
ing parenchyma by a distinct capsule of con- 
nective (?) or muscular fibers, joining metra- 
term at its anterior end to form eversible 
hermaphroditic duct. When everted, this duct 
forms a smooth bulbous prolapsus 0.27-0.4 mm 
wide and projecting out of the genital pore 
ventral to the pharynx. Hermaphroditic pouch 
bulbous, 0.33-0.5 X 0.45-0.5 mm, consisting 
of a compact mass of longitudinal and circular 
muscles. Whether there is a genital atrium or 
not could not be ascertained. 
Ovary 0.45-1.15 X 0.6-1. 2 mm, divided into 
four or five globular to oval lobes, situated close 
to center of body, a little to right or left of 
median line. Shell gland complex immediately 
posterolateral to ovary. Uterus coiling at first on 
right side of body posterior to right testis, 
dorsal to right cecum, then crossing over to left 
side across excretory vesicle ventrally, and wind- 
ing on left side of body posterior to left testis, 
dorsal to left cecum, finally occupying space 
between ovary and acetabulum, and between 
acetabulum and left testis; metraterm sigmoid, 
running ventral to convoluted vas deferens and 
