58 
PACIFIC SCIENCE, Vol. XIX, January 1965 
ulatory duct and prostatic duct with thick wall 
of circular muscle fibers. Prostatic duct may or 
may not be provided proximally with a small 
sphincter-like bulb. Prostate cells extensively de- 
veloped among vitelline follicles. Cirrus conical, 
unarmed, muscular, 10-15g long. Genital atrium 
thin-walled, apparently extending inwards down 
to the point where the uterus opens into it. 
Genital pore immediately posterolateral to left 
prohaptor. 
Ovary subglobular to oval, 0.07—0.23 X 0.09— 
0.32 mm; ootype medial to vas deferens curve; 
eggs about 120 X 80/x, with long filament. Uterus 
opening into genital atrium at a distance of 
about 0.3 mm from genital pore in the type. 
Vagina opening dorsally posterolateral to genital 
pore; vaginal duct crossing vas deferens coils 
ventrally and forming elongate seminal recep- 
tacle 50 fx wide in the type, latter opening into 
vitelline reservoir by a short narrow duct. Vitel- 
laria co-extensive with intestinal branches; vitel- 
line reservoir anterosinistral to ovary, 0.04-0.17 
X 0.05-0.3 mm. 
DISCUSSION: This genus resembles Pseudo- 
benedenia Johnston, 1931, m internal anatomy, 
especially in that the prostatic reservoir is en- 
closed in the cirrus pouch, but differs from it in 
possessing only one pair of rudimentary anchors 
instead of three pairs, and in the extensive de- 
velopment of prostate cells among the vitelline 
follicles. 
Dioncopseudobenedenia n. g. 
GENERIC DIAGNOSIS: Capsalidae, Benedenii- 
nae. Prohaptor sucker-like, partly with glandular 
tissue. Opisthohaptor disclike, aseptate, with scal- 
loped marginal membrane and only one pair of 
spines or anchors. Eyes present. Pharynx mus- 
cular or glandular. Intestinal limbs with inner 
and outer branches, not confluent posteriorly; 
outer branches united by longitudinal anasto- 
mosis parallel to principal limb. Testes juxta- 
posed, entire. Vas deferens winding in front of 
vitelline reservoir. Prostatic reservoir enclosed 
in cirrus pouch; prostate cells extensively de- 
veloped among vitelline follicles. Common geni- 
tal pore marginal or submarginal, immediately 
behind left prohaptor. Ovary entire, immediately 
pretesticular. Eggs filamented. Vagina with sub- 
marginal dorsal opening near genital pore. Vitel- 
line reservoir anterosinistral to ovary. Parasitic 
on gills of marine teleosts. 
type SPECIES: D. kala n sp., on Naso uni- 
cornis; Hawaii. 
2. Oligoncobenedenia nasonis n. g., n. sp. 
Fig. 2 
HABITAT: Gills of Naso h exacanthus; Hawaii. 
HOLOTYPE: U. S. Nat. Mus. Helm. Coll, S.Y. 
No. 2. 
DESCRIPTION ( based on 8 whole mounts ) : 
Body flattened, oval to elliptical, 1.6-2. 2 mm in 
length, with maximum width of 0.7-1. 0 mm at 
middle third. Opisthohaptor circular, 0.34-0.48 
mm in diameter, with scalloped marginal mem- 
brane which is 25/x wide in the type 2.0 mm 
long, with about 10 (14?) marginal booklets at 
somewhat irregular intervals. Immediately be- 
hind the central pit of the opisthohaptor there is 
a pair of large anchors typical of Benedenia, 
50-90 /x long, acute anteriorly and terminating 
in two blunt points posteriorly; middle pair oc- 
curring in Benedenia lacking entirely, posterior 
marginal anchor lacking in two out of 8 speci- 
mens; when present, it is 25-35g long, very nar- 
row, undulating, almost filiform, terminating in a 
minute claw posteriorly. Prohaptor oval, saucer- 
shaped, 0. 1-0.2 mm long, with glandular tissue 
along anterolateral margin; body fold between 
two prohaptors usually notched in median line. 
Two pairs of eye spots anterodorsal to pharynx. 
Pharynx glandular rather than muscular, 0.08- 
0.12 X 0.12-0.15 mm, without marginal inci- 
sion. Intestinal limbs ramified, but not united 
posteriorly. 
Testes oval to elliptical, closely juxtaposed in 
midregion of body, 0.22-0.35 X 0.18-0.33 mm, 
with two pairs of Goto’s organs immediately be- 
hind in median field; in the type the granular 
contents of the organ are massed together an- 
teriorly as if they were about to be emptied into 
the common efferent duct of the organ which 
passes forward between the two testes. Vas de- 
ferens containing granules of Goto’s organ along 
with sperm at its proximal end between ovary 
and left testis. After crossing the uterus dorsally 
the vas deferens turns back on itself, forming an 
elongate seminal vesicle, and then enters the cir- 
rus pouch at its base. Prostatic reservoir oval to 
elliptical, 100-180 X 60-100 /x, shuated longi- 
